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Topic: Best Weight Distributing Hitch with Sway Control?

Posted By: funhouse on 09/01/11 07:42am

Hello To All-

Could really use your help. My brother just purchased a Sunset Trail model ST29SS and will be towing it with a Ford F150 Platinum Truck. He will be driving from MA to PA to pick it up and drive home to MA in tow. My question is what is the best Weight Distributing Hitch with Sway Control to buy in your opinion? If you don't mind maybe your reasons and how difficult is the installation/setup? I know everyone has their favorites and their reasons.

Thanks in advance!


Best Regards, Bruce

Bruce & Ruth Kelly - Hingham, MA U.S.A.

2012 Itasca Navion 24J - Mercedes-Benz 6 Cylinder Diesel - FMCA F314386 - "Living The Dream"




Posted By: Sandia Man on 09/01/11 07:52am

The higher end hitches such as a Hensley and Propride provide the best performance and will cost a pretty penny. Other WD with sway control would be the Dual Cam and Equalizer brands which have good reviews on this forum.


Posted By: CampingN.C. on 09/01/11 07:54am

I am running a Reese straight bar with a Reese Dual Cam set up. I can't speak about anything else but there are a LOT of people running Equilizer set ups on here as well.
The installation (for me) was the easy part. Adjusting it to get it everything perfect was a LOT more time consuming.


2005 Chevrolet 2500HD CCSB 4X4 6.0 Bilstein shocks.
Reese Dual Cam.
2014 Jayco Jay Flight 32BHDS


Posted By: AZ T&T on 09/01/11 07:55am

I can't say what's best. I can say that I use an EqualIzer brand hitch and it works great and is very easy to use.


AZ T&T
2012 Jayco Eagle Super Lite 29.5RKS
2011 Chevy 2500 HD 4x4 Duramax
B&W Companion Hitch - Firestone Ride-Rite Air Bags
Honda EU2000i Generator


Posted By: crasster on 09/01/11 08:24am

I've NEVER once heard any complaints about Reese.


4 whopping cylinders on Toyota RV's. Talk about great getting good MPG. Also I have a very light foot on the pedal. I followed some MPG advice on Livingpress.com and I now get 22 MPG! Not bad for a home on wheels.



Posted By: Vvvv1010 on 09/01/11 08:52am

I use Pro Series WD and anti sway bar and really feel comfortable with the ride and control it provides. From what I understand, Pro Series is a product of Reese and it is less expensive than the Reese line.

WD and anti sway is important at all times and as long as you stay within the common, well known brands you will be fine. Hensley, Reese, Equalizer, Pro Series, etc...


2011 Jayco G2 32BHDS
2011 Ford F250 6.7L Turbo Diesel
2014 Lexus GX460 SUV



Posted By: APT on 09/01/11 09:23am

He should talk with his dealer about hitches they sell and can install for him. It takes 2-4 hours with the right tools to install and set up some of these. Not sure an RV newbie wants to do that and the PDI and buying paperwork.

Reese Straight Line and Equal-i-zer 4-point are similarly effective at about $500. Not worth saving $100 for anything else with sway control.

I like the Reese over EQ because it is quieter in operation and can be backed up with attached. It is a little more picky about being setup correctly.


A & A parents of DD 2005, DS1 2007, DS2 2009
2011 Suburban 2500 6.0L 3.73 pulling 2011 Heartland North Trail 28BRS
2012 VW Passat TDI


Posted By: kodiakcanuck on 09/01/11 09:32am

The Husky Centerline WDH with sway control that I use works very well. I have not experienced any sway with this set up, including passing trucks on the interstate. It is easy to hook up, and looked easy to install, but I had my dealer install it. I paid around $700 for it, but that's in Canada, I am sure it's cheaper in the US.

Here is a link for more info:
http://www.huskytow.com/FTP/PDF/P01045_HTCH_CenterLine.pdf


2011 Kodiak 240KSSL
Husky Center Line WDH
2014 Dodge Ram 1500 4x4 Outdoorsman 3:92,8-speed,5.7L HEMI
2007 Kodiak 214 HTT (prior)
2010 Dodge RAM 1500 4x4, 3:55, 5.7L (prior)



Posted By: keithinspace on 09/01/11 10:10am

APT wrote:

Not sure an RV newbie wants to do that and the PDI and buying paperwork.

I totally agree. It's a tough spot.

Unfortunately, the OP's brother is chosing to make a 6+ hour run to pick up the trailer. He needs to plan for it in whatever way he chooses. Best bet may be to "waste" $300 on a simple trunnion-bar WD hitch and drive home slow. An empty trailer may be just fine.

I installed my relatively difficult Hensley in about 4 hours without much more than a few wrenches and a good portable drill. That isn't out of the question if he plans for it. Heck...tow it to the nearest campground and do it the next day. Stranger things have happened!


2011 Gulf Stream Ameri-Lite 255BH
Hensley Arrow
2012 Ford F250 Lariat(6.7L Diesel, 3.55 gears, Crew with 6.5' Bed)
Me, Wife, Girl (9 YO), Boy (7 YO), Blind Beagle (108 YO), Tuxedo Cat (3 YO; 6 lives remaining)


Posted By: Center Pin on 09/01/11 10:39am

crasster wrote:

I've NEVER once heard any complaints about Reese.


You have now! I ditched my Reese DC because I was constantly having to "dial it in" always adjusting because one trip the back of the truck had 200 lbs of stuff, next trip had 2000 lbs, etc. When dialed in it was good, but I was always having to dial it in.


Trailer: 07 Tango 299BHS w/ 225/70R15 LT Load Range D

TV: 2004.5 Dodge 610 CTD 3500 QC 48RE 2wd Laramie SRW, FP Gauge, FASS 95/95, Rhino Lining, Hensley Arrow, Air Bags & Compressor, Canopy, Custom Boat Rack.
Been running B100 home brew June 2008!



Posted By: scottsnider on 09/01/11 10:43am

I switched from a w/d hitch and anti sway bar (friction type) to a Equal-i-zer and love the change and there is a different difference.


Posted By: barrelslime on 09/01/11 08:54am

THedges wrote:

I can't say what's best. I can say that I use an EqualIzer brand hitch and it works great and is very easy to use.

X2


Posted By: ljr on 09/01/11 09:05am

My opinion only but based of 1st hand experience...

Best = Pullrite. Very expensive and a royal pain to install. More or less permanently attached to the truck.

Almost as good = Hensley Arrow. Also very expensive but easy to install. Easily transferable from TT to TT. Nothing permanent on the TV but a standard 2" receiver.

Do you really need to spend that kind of money? Probably not. A reasonable TV/TT combination with any of the major brand hitches, properly setup, will do very well. If your willing to spend a bunch of money to go from "very well" to "very, very well"...that's your call. I did, a couple times.


Larry


Posted By: keithinspace on 09/01/11 09:19am

I would shadow Mr. LJR's comments. PullRite is as close to TT perfection as you can get, I guess, but it represents a very narrow market segment since it is a TRUCK thing, not a TRAILER thing. And it has a limited number of vehicles that can accept them...my Expedition, for example, is not included.

The "Best" solution is Hensley/ProPride. I can say that it is absolutely amazing.

The DualCam and Equalizer systems are a sway CONTROL system and not a sway ELIMINATION system, as are the first three mentioned above. Either of these systems may work very, very well for you. I've never owned either, so I cannot say.

Friction sway control is worthless. I wouldn't bother to waste the money.

Ever since I saw a Diesel Excursion almost "lose it" to sway while pulling a small-ish ~18' trailer at a reasonable speed on the DC beltway, I'm a big fan of making absolutely certain you have a good setup. This may include simply loading the trailer right (correct tongue weight) and keeping your speeds down. This may include any one of the above solutions.

I DO have a properly weighted trailer and am well within the stated capacities of my truck, but I still required the more "intense" hitches to improve my towing experience. One trip to Amish Country, and I'm here to say that having a good hitch is awesome and vastly improves your overall travel experience.


Posted By: jasoncw on 09/01/11 10:48am

APT wrote:

*snip* I like the Reese over EQ because it is quieter in operation and can be backed up with attached. It is a little more picky about being setup correctly.

I agree with the quieter operation, but if you grease it properly, it is relatively quiet. Not sure where you heard the deal about backing it up, but that is not the case with the Equal-i-zer. You are probably referring to a basic friction sway bar.


2011 Keystone Bullet Premier 31BHPR
2005 Ford Excursion 6.8L 3.73's, RAS, Equal-i-zer, P3



Posted By: RVbikers on 09/01/11 11:02am

I have the Reese DC system. It took me a good afternoon to get it set up, not installation, but hitch height, angle, etc all "dialed in" as mentioned above. I wouldnt trust a dealers set up. Its fine for them to install, and if they do set it up, take time to check measurements and find a place to make fine tune adjustments if needed. Its a great product, and as stated is sway control, not elimination, but it does a damn fine job of it. I hear great things and have seen the demo videos of the Hensley Arrow and I agree it seems to be a superior system but I believe they run around the $3k mark.


If you want all the comforts of home, stay there.
Jim & Evelyn +6
  • 2005 Ford Excursion V-10
  • 1999 Dutchmen 30BH2
  • 1998 Sportster 1200
  • 2000 Sporster 883



Posted By: usmc616 on 09/01/11 11:20am

Best bang for the buck is the Reese dual cam.


SEMPER FI
Joe,Joyce 4 kids & 3 dogs
2004 Ford Excursion LTD 4x4 V-10 3.73 Gears, Hellwig Swaybar, Bilstein Shocks & Steering Stabilizer, Roadmaster Active Suspension, Super Duty Tow Mirrors
Reese Dual Cam & Prodigy Brake Controller
2010 Jayco G2 32BHDS.


Posted By: wilcamp on 09/01/11 03:25pm

usmc616 wrote:

Best bang for the buck is the Reese dual cam.


X2!!!!!

I didn't have to fuss with the "dial it in" issues. I have a reliable dealership who did all that for me, and have never had the need to readjust anything. Having such a good service department isn't always a given, if you're driving the long distance to pick it up, but is a "priceless" asset for all your maintenance issues.


Wil, Tara, Nakeeta (Alaskan Husky 7 yr.-old), and Keeko (Jack Russel/Chihuahua mix 4 yr.-old)
2013 Jayco White Hawk 27 DSRB; 2010 Dodge Ram 1500 TRX4 Crew Cab 5.7L Hemi w/ 3.92 rear axle


Posted By: aftermath on 09/01/11 03:41pm

crasster wrote:

I've NEVER once heard any complaints about Reese.


Read this one.

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/25360846.cfm


2008 Toyota Tundra, Double Cab, 5.7L V8
2006 Airstream 25 FB SE
Equalizer Hitch
Prodigy Controler


Posted By: aftermath on 09/01/11 03:52pm

I have an Equalizer hitch and I am happy with it. I have used them on two different trailers and they have performed well. The Best? Well, I do believe that the HA or PP are the best from everything I have read on this forum. Of course, they are by far the most expensive so I would look into all the variables. If I had a very long trailer and a very short WB TV, I would go that direction for sure.

I have never owned anything other than the Equalizer so I won't say it is the best bang for your buck because I really don't know about the other types. I would stay away from any add on friction bar and go with a Reese or an Equalizer based on the majority input here on the forum.

The only reason I avoided the Reese was because I did not like having to disconnect before backing which was necessary back in the old days. Today they are much improved. My brother had one and I also didn't like snapping the chains into position. I suppose I am a bit of a wimp but this part did not appeal to me. Read through this thread to get a feeling of what I was thinking.

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/25369618.cfm


Posted By: zackyboy3rs on 09/01/11 04:26pm

Equalizer units.


2009 Chevy Silverado LTZ 2500HD 6.0L, 3.73, Gas sipper
2015 Jayco Eagle HT 27.5 RLTS


Posted By: evanrem on 09/01/11 08:25pm

Easy, HA or ProPride. I have a Propride and it is night and day over a standard wd hitch. Do a little research on it, everything you read is true.


Posted By: Ron Gratz on 09/02/11 08:40am

jerem0621 wrote:

I personally, am not a fan of the projected pivot point from a maneuverability stand point, same reason I prefer a TT to a Fiver.
If you are suggesting that maneuverability with a Hensley Arrow or ProPride hitch is similar to that of a Fiver, I think that is a misconception.

It is correct that these hitches "project" the pivot point about 4' forward when the TT is aligned with the TV.
However, as a yaw angle develops between TV and TT, the "Virtual Pivot Point" moves rearward and to the side.

At a relative yaw angle of about 4 degrees, the VPP has moved about 20" rearward from its most forward position and about 19" to the side of the TV's centerline.
At a relative yaw angle of about 15 degrees or more, the VPP has returned approximately to the location of the ball.

Since most maneuvering involves yaw angles of 15 degrees or more, the pivoting takes place near the location of the ball.
Some Hensley Arrow owners believe maneuverability is actually better than with a conventional hitch due to the added length of the HA placing the ball farther rearward of the TV's rear axle.

Ron


Posted By: jerem0621 on 09/01/11 11:36pm

Premium Hitches Explained

The BEST hitching systems REMOVES the ball coupler from the equation as the pivot point of the trailer

The three "premium" hitches out there, Pull-right, Hensley Arrow, and ProPride (3P) all work on this relatively simple principle.

The general idea of the premium hitches is to lock the trailer tongue to the ball in a rigid position and project the pivot point forward of the ball coupler. There is no torsional movement of the coupler on the ball in these three premium hitches. The pivot point is projected forward, and the axis movement on the ball is stopped.

Axis movement is ELIMINATED because the Ball coupler serves no other function other than to couple the trailer to the hitch/TV. With all three of the premium hitches sway is eliminated because of this Rigid connection the hitch creates to the TT and the TV.

Everything Else

The three hitches mentioned above do not rely on friction to control sway. They rely on pretty simple physics that eliminate sway start points such as the ball coupler itself from the equation.

Reese DC, Equal-i-zer, ETC rely on FRICTION of some type to reduce or eliminate sway. Some do it better than others. Reese DC and the Equal-i-zer (and their clones) do a great job when properly set up. However, EVERYTHING other than Hensley Arrow, 3P, and Pull-Right still rely on the ball coupler as the pivot point, this pivot point is a source of sway.

Are these "lesser" hitches inherently unsafe? NO they are not. Any WD hitch with sway control is much more safe than a TT simply dropped on a draw bar and coupler.

Personal Rant on Friction Sway Control

keithinspace wrote:

Friction sway control is worthless. I wouldn't bother to waste the money.


This is an entirely subjective statement supported only by subjective data related to ones personal experience.

It is like saying "rear drum brakes are worthless." It is simply not true.

I have dual friction sway control, traditional W/D hitch, and I have NO intentions of upgrading, why? After everything that I just said about the physics of the premium hitches, why would I settle for anything less?

Because I am satisfied with the experience.... and there are HUNDREDS of THOUSANDS of us out there who are satisfied with this type of sway control. (as there has been for the last 50 plus years)

Are there more expensive options out there? Yes. Are they better? Depends on the USER.

I will put my PROPERLY installed W/D hitch and Dual Friction sway control up against ANY improperly installed W/D hitch with or without integrated sway control (Hensley, 3P, Dual-Cam, etc. etc.)

Is it the best? For me, yes it is. I am happy that I learned the mechanics of my "Cheap Trunnion W/D Hitch" installed it correctly and added the Dual Sway control.

I personally, am not a fan of the projected pivot point from a maneuverability stand point, same reason I prefer a TT to a Fiver.

No modern W/D hitch and sway control device is JUNK. Some like DC, some like Equalizer, some like Hensley, some like add on friction sway control. Just like people, everyone has an opinion. Simply buy what design you like, match it to your trailer, and learn how to use it properly.

To the OP

Which W/D hitch with some sort of sway control is not nearly as important as actually installing the equipment correctly. All of the W/D hitches effectiveness is nullified if not installed properly.

It is not hard to do, simply grab some tools and the install instructions and make it right. Make sure you have some sort of sway control, even if it is a simple sway bar (they do actually work if installed correctly)

Don't forget to get a good proportional brake controller. This is a much more important safety issue.


Thanks!


2014 Chrysler Town And Country
3.6 Pentastar V6

"It's Kind of Fun To Do The Impossible"
~Walt Disney~


Posted By: xteacher on 09/02/11 04:48am

Another vote for the Dual Cam


Beth and Joe
3 Grown, Non-camping children
1 Future Camper - Granddaughter Alice (born 6/25/14 )
3 Camping Rescue Pups: Maddie (malti-poo/westie?), Sunny (toy poodle), and Jackson (boxer)

2014 Starcraft AR-ONE 14RB
2010 Nissan Pathfinder


Posted By: APT on 09/02/11 06:34am

jerem0621 wrote:


Reese DC...rely on FRICTION of some type to reduce or eliminate sway.


I do not agree with this. While there is some friction, the primary design element is more spring force on the bars from the bend/angle on the cam lobe.

Otherwise, a great post!


Posted By: ch47d99 on 09/02/11 06:46am

Certainly your best choice is the high end such as Hensley or ProPride, but if you don't want to spend several grand, then my vote is for the Equal-i-zer. I have been very happy with it. Certainly the Dual Cam and the newer Centerline offer as good performance, but I think those two have some significant drawbacks.

Just reading some of the install nightmares regarding the Dual Cam on this forum would have me running from that thing. One poster recently had a dealer screw up the install and now has permanent holes in his frame from a botched job. No thanks. Give me the no drill install of the Equalizer any day.

THe Centerline is a great idea, but the fact that you have to hook up basically in a straight line is a big concern for me. I didn't use to think so, but I have been in several spots now where a straight ahead hook up was not going to happen. I guess you could just drop it on the ball and pull out until you can get to a straight position, but it is still a bit of a hassle.


Posted By: Ron Gratz on 09/02/11 07:28am

APT wrote:

jerem0621 wrote:


Reese DC...rely on FRICTION of some type to reduce or eliminate sway.

I do not agree with this. While there is some friction, the primary design element is more spring force on the bars from the bend/angle on the cam lobe.
I agree with jerem0621.

The Dual Cam design relies on two forces:
1) the force of the cam acting perpendicular to the sloping surface of the bar, and
2) the friction force between cam and bar acting parallel to the sloping surface.

When the effects of friction are included, the yaw-resisting force is about 3-5 times greater than if there were no friction.

The Dual Cam also is different from other friction-based controls in that the yaw-resisting force is considerably less when the trailer is moving toward a centered position than when moving away from center.

Ron


Posted By: LAdams on 09/02/11 09:11am

I agree with Ron and I'll explain shortly...

From the standpoint of economical hitches there are basically 3 choices:

STANDARD HITCHES

Reese Dual Cam

Equal-i-zer

all other standard w/d hitches with friction sway control


Then there are the

PREMIUM HITCHES

Pullrite

Hensley Arrow

ProPride

The Hensley Arrow and ProPride are what is referred to as 4 bar linkage hitches... In simple terms, these premium anti-sway hitches project the ball pivot point forward under the tow vehicle... Both these hitches provide outstanding towing ability and cost in the area of $2000 - $3000 dollars

Pullrite

IMO, the best towing hitch available today. The Pullrite is essentially a 5th wheel hitch installed UNDER the tow vehicle... The pivot point of the TT is just to the rear of the tow vehicle differential and closely approximates a fifth wheel hitch. The Pullrite is also in the same price range as the Hensley and ProPride...

I used to tow with a Pullrite and it was rock solid under all towing conditions... There were/are several disadvantages to the Pullrite.

1.You have to lower the TV exhaust to clear the hitch

2.In many instances you lose your spare tire storage under the TV...

3.The hitch is somewhat vehicle specific and may or may not transfer over to a new tow vehicle.

4. Because the Pullrite handles very similar to a 5th wheel hitch, it requires exaggerated steering inputs to start the trailer turning. This caused some difficulties in my case, where I have limited room front and back while backing my TT in next to my garage...

The Hensley and ProPride are much more responsive to steering input and therefore easier for me to back in and keep the trailer straight and lined up with the garage... This task was much more difficult with the Pullrite so when it was time for me to upgrade to a hitch with more tongue weight capacity (My Pullrite was the 10K version - 1K tongue weight) I chose the Hensley...

All of the above mentioned hitches will do a good job assuming they are set up properly and are within their ratings... The premium hitches will do a better job, but there are thousands towing safely with the Reese, Equal-i-zer, and standard w/d hitches with friction sway control...

From my perspective, having towed with 3 different types of hitches as mentioned above (Standard w/d w/friction bar, Pullrite, Hensley) I believe that the Pullrite is the best hitch available. True, there are some disadvantages with it, but if I had a house where front to back clearance was not an issue, I would have a 20K Pullrite on my truck today...

Les


2000 Ford F-250SD, XLT, 4X4 Off Road, SuperCab
w/ 6.8L (415 C.I.) V-10/3:73LS/4R100
Banks Power Pack w/Trans Command & OttoMind
Sold Trailer - not RV'ing at this point in time



HUNTER THERMOSTAT INSTALL

HOME MADE WHEEL CHOCKS


Posted By: Jayco254 on 09/02/11 11:37am

If you're not going to use it a lot I wouldn't waste the money on a premium set up. I don't know how long are heavy your trailer is but I'm using a cheap Husky bent bar unit with 2 friction sway controls. I usually drive at 62 m.p.h. because I'm using st tires but with a 27 ft. 5600 lb. trailer I never have any trouble with sway and if set up right you can back up with out undoing the anti sway units. If you are pulling a heavy trailer at higher speeds and are going to be using it regular you might want to consider something nore on the premium side but I see a lot of bent bar units with single friction sways on good size trailers out there so they can't be to bad if set up right.


Tom, Kathy, Nikki, & Kelly
Pets: Lady - Texas Heeler, Dinger - Rhodesian Riidgeback Mix
2008 Ford Expedition Eddie Bauer 4x4 5.4 ci 3.73 gears
2008 Dodge Ram SLT Big Horn 4x4 5.7L Hemi 3.92 gears
2007 Jayco Jayfeather EXP 254
Husky W/D, P-3



Posted By: Wes Tausend on 09/09/11 03:14pm

...

Bruce,

I'll take a different tack and hopefully not confuse the OP over it. You are wondering what hitch to get and money certainly enters, or should enter, into the picture. Many Americans are notorious for over paying and over doing. I would say start with a normal economical hitch and work from there. As has been mentioned, many folks are satisfied, and never need to improve their hitch performance.

It doesn't matter which coupler/ball pivot WD hitch you get, except prices vary widely. They all do the same job about equally well unless mis-adjusted (and there are a couple of little known tricks to it). Everybody loves their own brand of just about anything, and you will hear some say how a new more expensive ordinary WD hitch was much better. Apparently their first WD hitch was mis-adjusted, although I understand many will vehemently deny this. They don't know any better. I will readily admit the two Hensley designed and PullRite hitches are better, but much more expensive, even used.

Because of the fact that all standard WD hitches are essentially the same, you shouldn't have to pay more than $230-250 dollars for a new one. A brand I whole-heartedly use, and recommend, is an Eaz Lift, currently selling here for $240 for the 1000# bar model. Built very similarily is this Curt hitch for even less, at only $233. I'll assume you can get friction pads for additional sway control, but you probably won't need them unless the empty TT design is faulty, which is quite unlikely nowadays. Something to keep in mind is some brand hitches, like the expensive Equal-i-zer imply they are friction-free, but depend on internal friction (pdf pages 19,23) non-the-less.

The reason I recommend Eaz Lift is that I accidentally received one with my last "pre-owned" TT, or I might not know any better. After a simple set-up, it worked flawlessly, even at high speeds on windy days. The TT was a 28 footer. The previous owner told me it worked great at his normal tow speed of 70 plus mph. I usually tow at about 55 for fuel economy (the heck with OPEC), but have been over 80 in a passing situation. I've also used the Eaz Lift on my latest TT, a 30 footer. I'll soon install my Hensley/ProPride hybrid and let this well matched Eaz hitch go with the ex TT.

I found out that Eaz Lift is not only just about the most economical hitch, but it was also the first WD hitch. I also found out that Eaz Lift still manufactures most of the WD springbars used by other, more expensive, brands. What the heck.

I mentioned there are a couple of set-up tricks to watch out for.

One is that the tow vehicle (TV) does not change bump-steer when loaded. Bump-steer is often misconstrued to mean that when a vehicle hits a bump, it causes the steering wheel to jerk. This is a complete misconception. Bump-steer is a term to describe a change in the toe-in/toe-out when the front suspension travels from bump (compression) to full droop (extended). If the front suspension height changes alignment much, especially going into a state of toe-out, when the TT is hooked up, the truck will wander like you wouldn't believe. It will feel like the rear axle is loose, but that isn't the problem. The problem is that the front tires are turned out slightly from one another and the result will be a combination that requires constant correction just to travel in a straight line. The instability will cause a built-in sway that cannot be corrected without correcting the toe-in. Believe it or not, you can eyeball this looking down the side of the front tires aiming rearward better than most alignment machines can do. DO NOT trust a recent "professional" computer alignment, especially along with new tires. It is obvious when supposedly correct toe-in is off, if one just bothers to look. In the end, the truck will steer better empty with correct toe-in too.

The second trick is something I didn't believe myself until I gave it a great deal of thought. The tilt of the hitchhead, the one that holds the WD bar pivots, makes a significant difference. While one might normally use this tilt just to get the needed chain-length vs weight distribution in range, it turns out the angle of the pivot can help center the TT. Most folks can see that the Reese cam hitch not only depends on friction, but also on gravity centering the cams. When the cams are out of their rest indentation, the entire hitch assembly, truck and TT tongue included, is lifted slightly by greater cam tension. The tendency is for the Reese cams to "settle back down" in the straight ahead position.

A similar, but even stronger, "settle back down" phenomena can be achieved by tilting the hitch head back on the shank on any hitch that has a spacer washer adjustment. While this may not make sense at first, I urge any doubters to go outside and observe how their hitch has to work, particularily when turning. Note that the bearing for the bar pivot is tilted back when the head is tilted. WITH THE HEAD TILTED BACK, this means that the bars natural position, dead center down the middle of the trailer, when not held by the chains (or other end fasteners) would be aimed down at the ground. However, if the same bar, even with the head tilted back, were to be unchained and swung 90 degrees to the side, for example, the pivot bearing (still vertical sideways) would merely cause the bar L end to twist to the back and rotate the bar, but the length of the bar may remain quite parallel with the ground.

What this all means is that the WD bar is normally partially swung out to the side to follow one side of the triangularly shaped tongue frame angle. So the bar is held down by some pivot bearing angle. Should the TT be turned, at least one of the bars will "straighten out", and be strained to point down even more, because the head bearing angle is now sharper. This will, in turn, lift the entire tongue/truck height, making the hitch resist this type turn force. The tongue/truck height finds that straight ahead is the preferred equilibrium gravity rest for the assembly. The reason this effect is stronger than the comparatively mild Reese cam action is that the tension is varied at the stiffest part of the WD bar.

So the trick is to set the head tilt back as far as possible and still allow reasonable clearance under the chained ends of the WD bars with correct tension overall. The idea principle came from an article by Andy Thomson of Canada, where they typically use much smaller tow vehicles for the weight than we do. Lacking our typical "Big Hammer" approach, they have to do it right.

Get insurance before the trip. Have fun and enjoy your new camper.

Wes
...

* This post was edited 09/09/11 03:23pm by Wes Tausend *


Days spent camping are not subtracted from one's total.
- 2000 Excursion V-10 - 2000 F-250 CC 7.3L V-8
- 2004 Cougar Keystone M-294 RLS, 6140# tare
- Hensley Arrow - Champion 4000w/3500w gen
- Linda, Wes and Quincy the Standard Brown Poodle
...


Posted By: Mr_MrsSchlepprock250 on 09/09/11 06:28pm

We tow a 30',7500# TT with a Ford F250 crew cab useing an Eaz-Lift WD hitch with one Eaz-Lift friction sway bar and it is VERY stable,it cost less than $400.00 out the door,I personally think it's rediculous to spend $2000 and $3000 on a hitch,I'm sure they're fine hitches,I can't say a thing bad,but when I can pull VERY stable and spend less than $400,well you know where I'm going...of course that's just my.02 worth...


Phil&April
'99F-250Superduty4x4/CrewCab/7.3
'04Tahoe4x4/5.3
Sierra/Forest River 30'TT
We used to have Johnny Cash and Bob Hope,now we have no cash and no hope.


Posted By: Ron Gratz on 09/09/11 06:54pm

Wes Tausend wrote:

So the trick is to set the head tilt back as far as possible and still allow reasonable clearance under the chained ends of the WD bars with correct tension overall. The idea principle came from an article by Andy Thomson of Canada, where they typically use much smaller tow vehicles for the weight than we do. Lacking our typical "Big Hammer" approach, they have to do it right.
Wes, the link takes us to a page containing a list of about 50 "hitch hints" articles by Thomson. I've not been able to find the one to which you refer. Can you tell us which one?

I'm interested in finding out if the "idea principle" which you attribute to Andy Thomson is the "Load Leveling Torque Effect" depicted in the graph on page 57 (72/154) of this report.

As the authors indicate on page 77 (92/154), load leveling torque induces a roll moment on the tow vehicle which tends to increase trailer damping.
Figure 35 on page 78 (93/154) indicates how a WD bar can induce a roll moment. However, note the articulation angle in the example illustration is approximately 25 degrees.
That is an angle which probably would not occur at highway speeds unless the TV/TT combination already were out of control.

I'll wait until I read what Andy Thomson has to say before I comment further on my opinion of the significance of WD-induced roll moment and its effect on trailer damping.

Ron


Posted By: Searching_Ut on 09/09/11 08:44pm

Without knowing how heavy the trailer is, and how much tongue weight is involved it's hard to say what I'd do. To be honest, most of the towing I've done over the years has been without any sort of sway control, or weight distrubution and I've never had issues. To pick the trailer up, if you're not over the hitch weight limit a simple drawbar/ball setup while keeping reasonable speeds might be a good option to avoid having to set up the hitch system at the pick up point.

As for which WD setup is best? I don't really have any input on that. Every system I've ever driven has seemed to be quite effective, although some are easier than others to hook up. Myself I kind of like the equalizer brand system. With it, when you first arrive at the campground, and drive around slowly, you get to announce your arrival to everyone. You then know that the people who smile and wave are friendly, and that you might want to avoid the ones how give you a dirty look. It can help speed up the site selection process, while at the same time keeping everything a little safer on the road.


Posted By: Wes Tausend on 09/13/11 05:27pm

Ron Gratz wrote:

Wes Tausend wrote:

So the trick is to set the head tilt back as far as possible and still allow reasonable clearance under the chained ends of the WD bars with correct tension overall. The idea principle came from an article by Andy Thomson of Canada, where they typically use much smaller tow vehicles for the weight than we do. Lacking our typical "Big Hammer" approach, they have to do it right.
Wes, the link takes us to a page containing a list of about 50 "hitch hints" articles by Thomson. I've not been able to find the one to which you refer. Can you tell us which one?

I'm interested in finding out if the "idea principle" which you attribute to Andy Thomson is the "Load Leveling Torque Effect" depicted in the graph on page 57 (72/154) of this report.

As the authors indicate on page 77 (92/154), load leveling torque induces a roll moment on the tow vehicle which tends to increase trailer damping.
Figure 35 on page 78 (93/154) indicates how a WD bar can induce a roll moment. However, note the articulation angle in the example illustration is approximately 25 degrees.
That is an angle which probably would not occur at highway speeds unless the TV/TT combination already were out of control.

I'll wait until I read what Andy Thomson has to say before I comment further on my opinion of the significance of WD-induced roll moment and its effect on trailer damping.

Ron


Ron,

I'm apologise I wasn't more clear on the reference to Andy Thomson. By highlighting Andy's name, rather than the word, "article", I meant only to further introduce him as a tech writer on camper dynamics.

I'm afraid the exact article is nowhere to be found on the internet since I have searched in vain for it. I was tipped off to the "hitchhead tilt effect" by another forum member, when I proposed that the only effect of tilting the hitchhead/WD bearing assembly was to adjust the range afforded the WD bar chain setting. I'm not sure if the other forum member initially fully understood the effect, but he did mention that Andy might not fully agree with me as per an article he had written. According to the other forum member, the article appeared in the 2010 Summer Issue of Airstream Life and was titled, WHY IS YOUR HITCH CROOKED.

You are correct that the roll moment tension also varies, and Andy addressed this even more thoroughly in the same article. Andy did use some pictures to more adequately explain these two phenomenen. I don't have any pictures, and I am not sure I can do it justice with mere words but I will give it a try. Pictures are worth a 1000 words, we all know.

Only when I looked directly at my hitch and imagined what would happen in 3D when the truck/hitchhead turned, did I understand myself. It is not easy to see. The trick is to first imagine the head bar-bearings perfectly vertical, then alternately imagine the bearings tilted back in a different scenario. With the hitchhead perfectly vertical, the bearings allow WD bars to swing perfectly level with the groundplane. But this is not true with a tilted hitchhead.

I did make a mistatement in my post above when I stated, "The reason this effect is stronger than the comparatively mild Reese cam action is that the tension is varied at the stiffest part of the WD bar." This is not a valid example. I believe the tilted head hitch merely bends the bars more than the cam roller escaping the Reese indentation, creating more tension off of "rest position", than does the Reese.

With the hitchhead tilted back, provided the TT were not in the way by being connected to the truck (only the tilted hitchhead and bars are attached), and with the WD bars swinging freely, one can see that the bars do not swing in an arc parallel with the groundplane, but rather in an arc that sweeps closer to the ground as the bars sweep straight behind the truck. And, conversely, a forward arc that would sweep continuously up away from the groundplane if the truck were not occupying that space. It is this change in groundplane, due to the tilt, that achieves the bar movement tension changes we are concerned with here.

As an example of bar movement, keep in mind, no matter the hitchhead tilt (if any), in a righthand turn, the turn will always make the left bar swing (as per TT attachment) from its normal outward angle (which is following the tongue frame angle) to a position more parallel with the longitudinal centerline of the truck, while the righthand WD bar will always be forced to swing out to a more acute angle with the truck centerline.

Imagine the hitchhead tilted with the TT attached, which tilts the WD bar bearings from vertical. Because both WD bars are always held somewhat parallel to the groundplane by the TT while in WD service, during a turn, the spring rate for a bar forced to swing to a straight rearward position, rearward of the truck centerline, increases more pounds under tension per inch, than is released by the other bar which travels to approach a 90 degree swing position, as opposed to the truck centerline, during the same turn. This is because the spring rates are not linear per inch of bend (travel). The net result is that the WD bars try to "rest" with the truck and TT inline straight ahead because the average combined tension is less. Actually, with the head tilted back, the chains should exhibit a pull, and very slight visible position, to the outside of the TT tongue, as each WD bar tries to swing outwards in it's prospective "tilted" bearing, to a position of lesser tension.

What this means is that if one were to do an imaginary experiment where one builds a small trailer frame supported only by a single castor wheel and the ball, the trailer would normally swing to any side (and even tip) while being towed straight ahead. But one could theoretically connect it by a ball hitch with a back tilted head WD system, and the castor wheeled trailer would follow the tow vehicle in an upright stable inline position. .....But if the head were tilted the other way, forwards, the trailer would remain still upright, but naturally seek either outside position rather than straight behind the vehicle. On a regular dual axle TT, I imagine this "tilted ahead" "un-centering" principle would encourage unwanted sway.....

Wes
...

* This post was last edited 09/13/11 05:43pm by Wes Tausend *


Posted By: Fix on 09/13/11 09:49pm

Reese Dual Cam.JHMO.






Posted By: Ron Gratz on 09/14/11 07:49pm

Wes Tausend wrote:

---The net result is that the WD bars try to "rest" with the truck and TT inline straight ahead because the average combined tension is less.---
Wes, I was pretty much with you to this point -- but now our views diverge.

Let's assume the bars' pivots are in planes which are parallel to a vertical plane passing through the TV's longitudinal centerline. The head's rearward tilt would cause a bar to be at maximum load when aligned parallel to the TV's centerline.

If the tilt is 15 degrees and the bar length is 30",
with the bar parallel to centerline, the rear of the unloaded bar would be 7.76" lower than the front of the bar.
With the bar at 25 degrees off center, the rear of the unloaded bar would be 7.04" lower than the front of the bar.
This means, when loaded, the load on the bar would be greater when parallel to the TV's centerline than when non-parallel.

Now, we should look at a situation where the TV and TT are aligned straight ahead and each bar is angled at 25 degrees from centerline. Assume head tilt is 15 degrees and each 30" bar is loaded to 1000#.

If the TT swings 5 degrees and the WD spring rate is 300#/inch,
the load on the bar which moves toward center will be increased to 1078#, and
the load on the bar which moves away from center will be decreased to 906#.
The net load on the two bars will decrease by 16#.

If the TT swings 10 degrees,
the load on the bar which moves toward center will be increased to 1139#, and
the load on the bar which moves away from center will be decreased to 797#.
The net load on the two bars will decrease by 64#.

My analysis shows that, if the hitch head has rearward tilt and TT swings to either side of centered,
the combined load on the WD (spring) bars will decrease.
I believe this is opposite to the conclusion you reached.

You stated,
The net result is that the WD bars try to "rest" with the truck and TT inline straight ahead because the average combined tension is less.
I interpret this to mean, if the TV/TT are not aligned straight ahead, the combined WD bar load will be greater.
Is this a correct interpretation?

We need to resolve this difference before we proceed to your other points.

Ron


Posted By: jimcatinmi on 09/15/11 06:16am

We have had three, started with a draw-tite round bar set up with friction sway control. It worked ok but didn't like having to stop and take off the sway bar before backing in. Switched to a equali-z-er
and loved it but when we had to get rid of our tt I thought we were done camping and sold it. But after a couple of years we r back to camping and we now have a reese dual cam (old style)that I bought used on cl and it works good also but I would have to say that the equali-z-er was the best of the three if I run across a good deal on a used one I will be switching back.


2012 Ford F-150 4x4 Max Tow Eco-Boost
2000 Jayco Eagle 266
Equal-i-zer
Barker 3500



Posted By: Wes Tausend on 09/15/11 01:59pm

Ron Gratz wrote:

Wes Tausend wrote:

---The net result is that the WD bars try to "rest" with the truck and TT inline straight ahead because the average combined tension is less.---
Wes, I was pretty much with you to this point -- but now our views diverge.

Let's assume the bars' pivots are in planes which are parallel to a vertical plane passing through the TV's longitudinal centerline. The head's rearward tilt would cause a bar to be at maximum load when aligned parallel to the TV's centerline.

If the tilt is 15 degrees and the bar length is 30",
with the bar parallel to centerline, the rear of the unloaded bar would be 7.76" lower than the front of the bar.
With the bar at 25 degrees off center, the rear of the unloaded bar would be 7.04" lower than the front of the bar.
This means, when loaded, the load on the bar would be greater when parallel to the TV's centerline than when non-parallel.

Now, we should look at a situation where the TV and TT are aligned straight ahead and each bar is angled at 25 degrees from centerline. Assume head tilt is 15 degrees and each 30" bar is loaded to 1000#.

If the TT swings 5 degrees and the WD spring rate is 300#/inch,
the load on the bar which moves toward center will be increased to 1078#, and
the load on the bar which moves away from center will be decreased to 906#.
The net load on the two bars will decrease by 16#.

If the TT swings 10 degrees,
the load on the bar which moves toward center will be increased to 1139#, and
the load on the bar which moves away from center will be decreased to 797#.
The net load on the two bars will decrease by 64#.

My analysis shows that, if the hitch head has rearward tilt and TT swings to either side of centered,
the combined load on the WD (spring) bars will decrease.
I believe this is opposite to the conclusion you reached.

You stated,
The net result is that the WD bars try to "rest" with the truck and TT inline straight ahead because the average combined tension is less.
I interpret this to mean, if the TV/TT are not aligned straight ahead, the combined WD bar load will be greater.
Is this a correct interpretation?

We need to resolve this difference before we proceed to your other points.

Ron


Ron,

Sorry about the delay. This is turning out to be one of those 100+ hour work weeks again.

We are seeing most of the situation the same. I'm not sure just how you came up with different loads on the bars when I surmised they move the same degree (i.e. same distance), and should give and take equally with a constant spring rate, say 300#/inch. I am sure you thought the geometry over carefully, and might enlighten me why this is not so. I would have guessed that if the bars were truly a linear (constant) spring rate, that the loads would completely "even out", or cancel. I think the entire "centering" process Andy promoted, counts on the bars being of a progressive spring rate, and I believe that is what Andy implied, and why I said I believed the, "average combined tension is less". After some thought I agreed with his assessment, not only that the loads would favor a centering, or "settling" as he put it, to track the TT behind the tow vehicle, but that the WD bars are progressive in their changing position reaction to strain.

I typed out his second to last paragraph in the article shown below. I know you have a copy, but others may not.
Quote:

...Beyond making the tow vehicle much easier to control in an emergency manuever, the ball mount angle assists with directional stability going straight down the road at highway speeds. Even in small degrees of direction change, the torsion bar on the outside of the turn gains tension much faster than the bar on the inside loses tension. This is because as a torsion bar bends, it requires progressively more effort to bend it the same distance. With angle on the ball mount, the trailer wants to naturally settle in a position straight behind the tow vehicle...


For those that aren't sure, by progressive spring rate, I mean that such a spring may increase 300# the first inch of bend, but more (perhaps 350#) the second inch of bend, and even more the next inch etc. A simple sealed cylinder and piston should increase in a linear fashion, per it's percent of reduced volume, as air compresses, but bent spring metal may not always follow this, as some coil springs are purposely progressively wound.

I am perhaps assuming incorrectly, that WD bars are of a progressive nature, which is not very scientific. Since I think all of this hinges on spring rate, perhaps an empirical experiment could be done where one jacks the end of the "tilted" bars at different angles to the truck centerline, but with a bath scale under the jack. If the bars were jacked with increasing measured inches of bend, and at various angles to the truck centerline, would this not be indicative of their behavior while in "tilted" WD TT service?

Wes
...


Posted By: Ron Gratz on 09/15/11 08:05pm

Wes Tausend wrote:

I typed out his {Andy Thomson's} second to last paragraph in the article shown below. I know you have a copy, but others may not.
Quote:

...Beyond making the tow vehicle much easier to control in an emergency manuever, the ball mount angle assists with directional stability going straight down the road at highway speeds. Even in small degrees of direction change, the torsion bar on the outside of the turn gains tension much faster than the bar on the inside loses tension. This is because as a torsion bar bends, it requires progressively more effort to bend it the same distance. With angle on the ball mount, the trailer wants to naturally settle in a position straight behind the tow vehicle...
With due respect to Andy, I believe this entire paragraph is fundamentally wrong.

A WD bar does not require "progressively more effort" to bend it the same distance as the bending increases. A WD bar is made of a single piece of steel, and steels exhibit a very nearly linear stress-strain relationship up to a well-defined point called the "yield point".

ORF member, John Barca, has measured load-deflection values for two actual WD bars. His results are reported in this post. If you plot his values, you'll see that, within his experimental error, the relationship is linear.

Another member, nvreloader, has measured front-axle loads using varying numbers of tilt washers and tensioned chain links. His results are reported in this post. If you analyze his values, you'll also see a linear relationship between number of washers and load transfer and between number of links and load transfer.

Since Andy's claim of a "progressive" relationship is key to his conclusions, it would be good for him to provide proof of such. Otherwise, I can see no basis for such a claim, and I think it is misleading.

As I tried to explain in my previous post, there is a non-linear relationship between WD bar load and bar yaw angle. However, the non-linearity is in an opposite direction to which Andy described when he stated, "Even in small degrees of direction change, the torsion bar on the outside of the turn gains tension much faster than the bar on the inside loses tension."

According to Andy, "When the trailer is straight behind the tow vehicle the bars are 4" off the ground. When the torsion bar itself if straight behind the tow vehicle, it swings to as low as 3" off the ground." This means the bar reaches a minimum height and then would begin to rise if the yawing continued in the same direction.

One characteristic of a minimum (or maximum) point is that the rate of change of (in this case) bar height versus yaw angle is zero at the minimum point. This means that, as the bar swings through the minimum, the angle increases but the height does not. Or, if the height of the bar is fixed by the chain, as the bar becomes straight behind the tow vehicle, the yaw angle increases but the bar load does not.

As the articulation increases, the bar on the outside of the turn moves closer to the TV's centerline, and the load on the bar increases. The rate of load increase becomes less and less as the bar approaches parallel to the TV's centerline.

The bar on the inside of the turn is moving away from the TV's centerline, and the load on the bar decreases. The rate of load decrease becomes greater and greater as the bar gets farther from the TV's centerline.

The rate of change of bar height versus angle will be maximum when the bar is at 90 degrees to the TV's centerline. If the bar could continue to swing forward, the rate of change would decrease until becoming zero when the bar was pointing forward and parallel to the TV's centerline (and had reached its maximum height).

Quote:

For those that aren't sure, by progressive spring rate, I mean that such a spring may increase 300# the first inch of bend, but more (perhaps 350#) the second inch of bend, and even more the next inch etc. A simple sealed cylinder and piston should increase in a linear fashion, per it's percent of reduced volume, as air compresses, but bent spring metal may not always follow this, as some coil springs are purposely progressively wound.
Coil springs can be made to become progressively stiffer as explained here. However, to make a WD bar be "progressive", you would have to attach some "stops" to the A-frame which could limit the curvature of the bar as it continues to be loaded. Or, you could build it as a leaf spring.

Quote:

I am perhaps assuming incorrectly, that WD bars are of a progressive nature, which is not very scientific. Since I think all of this hinges on spring rate, perhaps an empirical experiment could be done where one jacks the end of the "tilted" bars at different angles to the truck centerline, but with a bath scale under the jack. If the bars were jacked with increasing measured inches of bend, and at various angles to the truck centerline, would this not be indicative of their behavior while in "tilted" WD TT service?
I think it mostly would be indicative of the TV's roll stiffness. As you increase the yaw angle, you increase the roll-axis torque being applied to the TV, and the TV will roll.

Ron

* This post was edited 09/16/11 06:05am by Ron Gratz *


Posted By: Wes Tausend on 09/18/11 11:58pm

Ron Gratz wrote:

Wes Tausend wrote:

I typed out his {Andy Thomson's} second to last paragraph in the article shown below. I know you have a copy, but others may not.
Quote:

...Beyond making the tow vehicle much easier to control in an emergency manuever, the ball mount angle assists with directional stability going straight down the road at highway speeds. Even in small degrees of direction change, the torsion bar on the outside of the turn gains tension much faster than the bar on the inside loses tension. This is because as a torsion bar bends, it requires progressively more effort to bend it the same distance. With angle on the ball mount, the trailer wants to naturally settle in a position straight behind the tow vehicle...
With due respect to Andy, I believe this entire paragraph is fundamentally wrong.

A WD bar does not require "progressively more effort" to bend it the same distance as the bending increases. A WD bar is made of a single piece of steel, and steels exhibit a very nearly linear stress-strain relationship up to a well-defined point called the "yield point".

I agree with you up to a degree. Steels do exhibit a very nearly linear stress-strain elastic relationship up to a well-defined point called the "yield point" (or plastic deformation point). I searched the net in vain for a good example of non-linear progressive relationship. All I found was this brief mention (last sentence of paragraph) that,
Quote:

"Coil springs and other common springs typically obey Hooke's law (that is linear). There are useful springs that don't: springs based on beam bending can for example produce forces that vary nonlinearly with displacement."


So I looked for an internet example of a type of beam deflection that would indicate a non-linear property, but I didn't find it. By intuition, I concentrated on tapered beams, which are not usually used in constructing buildings or bridges, and info was pretty meager.

But before we decide that WD bars are likely not progressive, we should consider one thing. I notice that many WD bars are tapered. You can see this in the pictures of Andy's round WD bars in his article. I also have a set of round bars with my Eaz Lift hitch, and they are tapered too. I said earlier in this thread that Eaz Lift makes many of the bars for other manufacturers, although I have long lost the link that told me this. If Eaz Lift does make these bars, they are likely all tapered. Other square WD bars (trunnion type) also show a taper in pictures of hitches. I think this tapered feature may provide the progressive bending I am looking for. Lacking a good reference, let me explain my reasoning.

I think a similar example of a non-linear tapered beam would be a tapered fishing rod. With a little imagination, imagine how flimsy a rod would be if it were all the thin diameter throughout it's length. Or how stiff and insensitive it would be if the entire length were the thickness of the base. I think what a tapered beam, or fish pole in this case, does is develop a progressive spring rate property to an otherwise straight linear beam. Shorter spring lengths of the same diameter are stiffer. The thickening "taper" diameter effectively shortens the length of the thinner parts, making the overall assembly progressively stiffer as it bends. This goal is literally why the rods are tapered.


ORF member, John Barca, has measured load-deflection values for two actual WD bars. His results are reported in this post. If you plot his values, you'll see that, within his experimental error, the relationship is linear.

I'm afraid I didn't have time to fully analyze this. Offhand, some of it seemed progressive and other parts more linear.

Another member, nvreloader, has measured front-axle loads using varying numbers of tilt washers and tensioned chain links. His results are reported in this post. If you analyze his values, you'll also see a linear relationship between number of washers and load transfer and between number of links and load transfer.

I ran out of time here.

Since Andy's claim of a "progressive" relationship is key to his conclusions, it would be good for him to provide proof of such. Otherwise, I can see no basis for such a claim, and I think it is misleading.

It does seem if we could agree that tapered bars are progressive, we could meet Andy's claim and find he was correct. I'm not sure all bars are tapered though, and I cannot prove that a tapered beam bends progressively by outside reference.

As I tried to explain in my previous post, there is a non-linear relationship between WD bar load and bar yaw angle. However, the non-linearity is in an opposite direction to which Andy described when he stated, "Even in small degrees of direction change, the torsion bar on the outside of the turn gains tension much faster than the bar on the inside loses tension."

I'm still lost as to how you came to this conclusion, Ron. If what you say is true, then such tilted bars would always introduce an instability to the camper trailing straight behind the tow vehicle. My thought-experiment example, in my earlier post, of a castor wheeled trailer supported by WD bars "bent back" would act as I predicted the "bent forward" bars would and vice-versa, a new-found stability would be found for the "bent forward" hitch head.

According to Andy, "When the trailer is straight behind the tow vehicle the bars are 4" off the ground. When the torsion bar itself if straight behind the tow vehicle, it swings to as low as 3" off the ground." This means the bar reaches a minimum height and then would begin to rise if the yawing continued in the same direction.

One characteristic of a minimum (or maximum) point is that the rate of change of (in this case) bar height versus yaw angle is zero at the minimum point. This means that, as the bar swings through the minimum, the angle increases but the height does not. Or, if the height of the bar is fixed by the chain, as the bar becomes straight behind the tow vehicle, the yaw angle increases but the bar load does not.

I can see this.

As the articulation increases, the bar on the outside of the turn moves closer to the TV's centerline, and the load on the bar increases. The rate of load increase becomes less and less as the bar approaches parallel to the TV's centerline.

I don't think the load becomes less until it passes the centerline. Up to the centerline the angle increases linearly and the increased load would either be linear in the case of linear WD bar springing, or progressive in the case of progressive WD bar springing.

The bar on the inside of the turn is moving away from the TV's centerline, and the load on the bar decreases. The rate of load decrease becomes greater and greater as the bar gets farther from the TV's centerline.

I follow.

The rate of change of bar height versus angle will be maximum when the bar is at 90 degrees to the TV's centerline. If the bar could continue to swing forward, the rate of change would decrease until becoming zero when the bar was pointing forward and parallel to the TV's centerline (and had reached its maximum height).

I don't follow. The rate of change will always be linear as the bar sweeps 0 to 90 degrees, and beyond to 180, as far as I can see. After 180, yes it would go down if the WD bar could swing all the way around. Perhaps you are thinking on the order of of non-linear piston acceleration movement when connected by a rod to a crankshaft.

Quote:

For those that aren't sure, by progressive spring rate, I mean that such a spring may increase 300# the first inch of bend, but more (perhaps 350#) the second inch of bend, and even more the next inch etc. A simple sealed cylinder and piston should increase in a linear fashion, per it's percent of reduced volume, as air compresses, but bent spring metal may not always follow this, as some coil springs are purposely progressively wound.
Coil springs can be made to become progressively stiffer as explained here. However, to make a WD bar be "progressive", you would have to attach some "stops" to the A-frame which could limit the curvature of the bar as it continues to be loaded. Or, you could build it as a leaf spring.

You are quite right about progressive wound springs. That was not a good example for me to use. A leaf spring might be considered a progressive spring either as a homogeneous tapered assembly where the leaves are clamped tight as one, or perhaps as a set of variable "stops" used as a common sliding spring-leaf apparatus. I also think I'm dead wrong about the piston/sealed cylinder I explained above. The piston/cylinder is only linear when the volume is continuously halved... I think. But if the piston increasingly moves in equal stroke lengths, it becomes a progressive spring in pressure (air springing).

Quote:

I am perhaps assuming incorrectly, that WD bars are of a progressive nature, which is not very scientific. Since I think all of this hinges on spring rate, perhaps an empirical experiment could be done where one jacks the end of the "tilted" bars at different angles to the truck centerline, but with a bath scale under the jack. If the bars were jacked with increasing measured inches of bend, and at various angles to the truck centerline, would this not be indicative of their behavior while in "tilted" WD TT service?
I think it mostly would be indicative of the TV's roll stiffness. As you increase the yaw angle, you increase the roll-axis torque being applied to the TV, and the TV will roll.

You are right about the truck roll stiffness being part of the result. I guess it would be indicative of the entire set of springs, truck and WD bars. Perhaps a better way to minimise the truck movement would be to block the front truck frame, and also the back truck frame after lifting it enough to prevent additonal lift acquired from test-lifting the bars.

Ron


What do you think about the tapered WD bar possibility? Would it possibly change the result? Could Andy be correct? I'm hoping to get a couple of days off work starting Tuesday, and maybe I'll be able to think about this more clearly.

Wes
...



Posted By: Ron Gratz on 09/19/11 06:16am

Wes Tausend wrote:

What do you think about the tapered WD bar possibility? Would it possibly change the result? Could Andy be correct? ...
Wes, I'm off to build houses again this morning. This is the best I can offer in the time available:

Example 6.11 Tapered Cantilevers at bottom of page 343.

The equation for deflection versus load is at the top of page 345.
The deflection is directly proportional to load.

More this evening.

Ron


Posted By: Wes Tausend on 09/19/11 09:16am

Ron Gratz wrote:

Wes Tausend wrote:

What do you think about the tapered WD bar possibility? Would it possibly change the result? Could Andy be correct? ...
Wes, I'm off to build houses again this morning. This is the best I can offer in the time available:

Example 6.11 Tapered Cantilevers at bottom of page 343.

The equation for deflection versus load is at the top of page 345.
The deflection is directly proportional to load.

More this evening.

Ron


Thanks Ron,

Now I have slept the night and I thought I was going to work before noon, but the lineup has dropped and I see I am not due east out of Glendive until after 7 tonight.
I was hoping for a day trip rather than spend my first day off sleeping to recover the lack thereof.

But for now I have worked during the day, slept at night, and am somewhat rested and sane.

I always thought a cantilever beam required some sort of fulcrum, but it does not. It may also be the end connected type beam we are discussing, and a WD bar as a "cantilever beam" is a much better description per thefreedictionary.com/cantilever:
Quote:

cantilever:
1. A projecting structure, such as a beam, that is supported at one end and carries a load at the other end or along its length.


I gave some more thought to the fishing rod parable, and I believe it would definately eventually be obviously progressive. One might think that if a small fish were caught, the tip would bend down somewhat in a small curve. But when a larger fish were caught, the rod tip would bend down to such a degree that it would form a sort of parabola with the tip pointing directly down. At this position the small tip would cease to bend because it would aim directly in the direction of the force acting upon it... down (per the heavy fish). Now the rod must certainly bend a thicker portion of the rod which would logically bend (give) less per pound. In other words we have achieved a progressive springing effect in this case. I submit that tapered fish-rod bending is always somewhat progressive because the tip always moves further approaching parallel with the direction of force, even with a small fish. I further submit that this is also true of a WD bar, even though the bend is very minute.

On the other hand, why would a manufacturer go to the trouble to taper a WD bar? One reason, not to do with any progressive plan, would be to distribute the stress more evenly along the bar. As an example, look at the constant cross-section bar in your book link in Fig 6.20, page 342. One can see it is bent close to the attachment, but straighter at it's far length. This makes sense because the leverage, therefore the stress, is concentrated at the near end to the attachment. So a cantilevered WD bar apparently needs to be tapered to equally distribute the stress, and avoid breaking near the attachment. But does the taper also furnish a progressive rate? I don't know, but I still suspect so.

Let us refer back to your book link (great find, by the way).

By the formula's given, I'm inclined not to initially believe that a tapered beam, deflected in cantilever, is still linear. Otherwise the equations for end deflection of a uniform cross section versus a varied (tapered cantilever) cross section would logically be the same. But the book does warn that a different equation must be used for apparent different results... other than linear I presume. What is not linear must be non-linear.

I note that, in the deflection equation, v(L)= -FL³/EI?{-8In 0.5-5}= -0.5452 FL³/EI?, for a tapered cantilever, the force-length, "FL", is exponential, and the denominator is not, which leads me to believe the deflection cannot be linear for various added equal increments of additional force. Please forgive my rendition of the formula as I cannot read it well on my netbook, and the script code will not let me expand the page.

I wonder if anyone else on the forum is reading all this, or even enjoying it. It is a complicated subject, and good mental exercise. My apologies to the original poster, Bruce, if we have gotten carried away with details here.

Wes
...

* This post was edited 09/19/11 09:24am by Wes Tausend *


Posted By: Sean Boburk on 09/19/11 09:49am

I can't compare to anything else, since I have only had a 4 point equalizer. But I will say, the dealer I purchased mine from, did not install it correctly. My ball was too low, and the brackets that bolt to the TT were installed upside down.

As to the actual equalizer install...the latest instructions say to add washers until you remove half, to all of the TV front end rise. From my experience, I would set it up to remove pretty much all of the rise. I had mine between, and once I added another washer (only taken one trip since doing this) it seems much more stable. If I remember correctly, mine was at 37 inches unloaded, 37.5 loaded with no WD, and 37.25 with WD, with the amount of washers the instruction say to start at (4?). I added one more washer, taking it to just a hair over 37 with WD...and it seems much more stable.

Just my 2 cents.
Sean

* This post was edited 09/22/11 07:15am by Sean Boburk *


2011 Flagstaff 29SKBS
2010 F-150 4x4 5.4L
2011 camping days=23 in 9 locations
2012 camping days=4 in 2 locations


Posted By: Ron Gratz on 09/19/11 09:25pm

Wes Tausend wrote:

Andy Thomson wrote:

...Beyond making the tow vehicle much easier to control in an emergency manuever, the ball mount angle assists with directional stability going straight down the road at highway speeds. Even in small degrees of direction change, the torsion bar on the outside of the turn gains tension much faster than the bar on the inside loses tension. This is because as a torsion bar bends, it requires progressively more effort to bend it the same distance. With angle on the ball mount, the trailer wants to naturally settle in a position straight behind the tow vehicle...
For those that aren't sure, by progressive spring rate, I mean that such a spring may increase 300# the first inch of bend, but more (perhaps 350#) the second inch of bend, and even more the next inch etc. ---

I am perhaps assuming incorrectly, that WD bars are of a progressive nature, which is not very scientific. Since I think all of this hinges on spring rate, ---
Wes
...
Wes, I think we need to take a deep breath and consider what we mean when we use the term, "spring rate", as used in the above quoted excerpts from previous posts.

We are attempting to discuss "spring rate" for a weight distribution bar. The classical definition of "spring rate", for this case, is the ratio of incremental load divided by incremental deflection -- often expressed in pounds per inch.

For a WD bar, the magnitude of deflection is relatively small compared to the length of the bar, and the length of the bar and other properties of the bar are assumed to remain constant. The distance from the fixed end of the bar to the point of load application also is assumed to remain constant. The two variables, therefore, are deflection and load.

As mentioned previously, John Barca has posted load-deflection data for two WD bars -- an 800# Reese HP trunnion bar and a 1200# Reese HP trunnion bar. These data can be used to calculate an estimate of spring rate.

To explore the possibility that the spring rate might be non-linear, a second-order polynominal (parabolic) curve was fit to the values for load versus deflection.

For the 800# bar, the curve fitting gave: Load = 375xDeflection - 15.5xDeflectionxDeflection
The spring rate is the slope of this equation which gives: Spring Rate = 375 - 31xDeflection
The spring rates for various values of deflection are:

Deflection--Spring Rate
(inches)------(lbs/inch)

-----0------------375
-----1------------344
-----2------------313
2 3/8------------301

For the 1200# bar, the curve fitting gave: Load = 402xDeflection - 30.7xDeflectionxDeflection
The spring rate is the slope of this equation which gives: Spring Rate = 402 - 61.4xDeflection
The spring rates for various values of deflection are:

Deflection--Spring Rate
(inches)------(lbs/inch)

-----0------------402
-----1------------341
-----2------------279
-----3------------218
3 1/4------------202

For both bars, the data indicate the spring rate decreases with increasing deflection and load. This indication is opposite to the opinions expressed in the quoted text above.

If we combined the two sets of data obtained by John, the numbers would represent a slightly "regressive" WD bar which gains 368# in the first inch of bend, 312# in the second inch of bend, and 256# in the third inch of bend. As the bars were bent, they required "progressively" less effort to bend them the same distance.

If our objective is to understand how "head tilt" affects the interaction between the WDH and the TV, then, IMO, there is nothing to be gained by continuing the discussion of whether the WD bar has a "progressive spring rate".

However, I think there is much to be gained by discussing things such as:
differences in the "orbits" of the ends of the WD bars for vertical head versus tilted head,
how differences in orbit affect WD bar loading,
and how differences in orbit and loading affect pitch and roll torque applied to the TV.

Ron


Posted By: Wes Tausend on 09/22/11 05:47am

Ron Gratz wrote:

Wes, I think we need to take a deep breath and consider what we mean when we use the term, "spring rate", as used in the above quoted excerpts from previous posts.

We are attempting to discuss "spring rate" for a weight distribution bar. The classical definition of "spring rate", for this case, is the ratio of incremental load divided by incremental deflection -- often expressed in pounds per inch.

For a WD bar, the magnitude of deflection is relatively small compared to the length of the bar, and the length of the bar and other properties of the bar are assumed to remain constant. The distance from the fixed end of the bar to the point of load application also is assumed to remain constant. The two variables, therefore, are deflection and load.

As mentioned previously, John Barca has posted load-deflection data for two WD bars -- an 800# Reese HP trunnion bar and a 1200# Reese HP trunnion bar. These data can be used to calculate an estimate of spring rate.

To explore the possibility that the spring rate might be non-linear, a second-order polynominal (parabolic) curve was fit to the values for load versus deflection.

For the 800# bar, the curve fitting gave: Load = 375xDeflection - 15.5xDeflectionxDeflection
The spring rate is the slope of this equation which gives: Spring Rate = 375 - 31xDeflection
The spring rates for various values of deflection are:

Deflection--Spring Rate
(inches)------(lbs/inch)

-----0------------375
-----1------------344
-----2------------313
2 3/8------------301

For the 1200# bar, the curve fitting gave: Load = 402xDeflection - 30.7xDeflectionxDeflection
The spring rate is the slope of this equation which gives: Spring Rate = 402 - 61.4xDeflection
The spring rates for various values of deflection are:

Deflection--Spring Rate
(inches)------(lbs/inch)

-----0------------402
-----1------------341
-----2------------279
-----3------------218
3 1/4------------202

For both bars, the data indicate the spring rate decreases with increasing deflection and load. This indication is opposite to the opinions expressed in the quoted text above.

If we combined the two sets of data obtained by John, the numbers would represent a slightly "regressive" WD bar which gains 368# in the first inch of bend, 312# in the second inch of bend, and 256# in the third inch of bend. As the bars were bent, they required "progressively" less effort to bend them the same distance.

If our objective is to understand how "head tilt" affects the interaction between the WDH and the TV, then, IMO, there is nothing to be gained by continuing the discussion of whether the WD bar has a "progressive spring rate".

However, I think there is much to be gained by discussing things such as:
differences in the "orbits" of the ends of the WD bars for vertical head versus tilted head,
how differences in orbit affect WD bar loading,
and how differences in orbit and loading affect pitch and roll torque applied to the TV.

Ron


Ron,

Well I guess I'll give up at this point... at least for a while. I think you are right, we have reached an impasse searching for an agreement of likely WD bar spring rating properties.

In spite Of Andy's belief that the bars are progressive in nature, plus the tapered beam formula you linked indicating a nature of progressive deflection, and my elaborate explanation why this may be so, you have apparently slaughtered my beautiful explanation theory with ugly facts.

I did also get regressive results when I read John's results directly, although they don't match yours. As an example John measured 1 inch deflection in the 800# bar at 375# load and a deflection of 2 inches only 325# more later at 700# load. The second inch of deflection only took 325# load as opposed to the first inch that required 375# load.

At this point I do not understand why John Barca's measurements do not match my supposition, but, as you do, I do trust his careful attention to detail. I cannot begin to explain why such tapered beam deflection, that of WD bars, would be regressive, but I must admit that may be the case if that is what John measured. It is important to me to be able to understand not just what, but precisely why things happen as they do, so I will tuck an analysis of John's results away for another day when I have more time and just start a new thread.

I believe there are some consequences if WD bar springing is truly regressive. The most astounding (to me anyway) would be the tendency for the TT to not track behind the tow vehicle. The center position, the one that I (and Andy) supposed would be at a low center of "rest" gravity, would now be a high point with lower rest found to either side. Intuitively, I (assume ) this applies to all WD sprung hitches, but you know what they say about intuition.

In regard to applying to all WD hitches, now there is a case for encouraging "Hensley bump", or as I believe you have suggested in the past, the "4-bar linkage bump". But, the way I see it, contrary to the direction Andy has suggested, all this could then theoretically be avoided by tilting the hitch forward to obtain the opposite result. Tilting the hitch forward would therefore provide additional stability in the case of "regressive springing". And, interestingly enough, John Barca's hitch does appear to be tilted forward in his photo:


I'm inclined to think a second data confirmation experiment would not be a bad idea. I did think of a much better way (similar to John's) to measure loading on the WD bars, at least static loading. I would still need a tongue scale such as John used, or at least follow known ways of loading my trusty "propane bath scale" by weight reducing leverage methods. All that need be done is to park my hitched rig on a flat surface such as a local plaza parking lot. The rig would be parked in various states of turn and measurements taken. The measurements would consist of merely applying a lifting force to the ends of the WD bars until loose slack barely appears in the chain. The resultant weight reading should indicate current bar loading. Comparing one side (bar) to the other should indicate whether one side has gained more weight than the other side has lost by ignoring deflection altogether. One other difference between my method and John's, would be that I would not bear any weight on the TT tongue jack.

This measurement is easier said than done, however. I spent yesterday afternoon retrieving my camper from the dealership, building a small bridge, getting it in my driveway and doing some repairs until company arrived (the second evening in a row). Even though this latest camper has more clearance, it still does not clear my confounded driveway dip. And there is no way my DW will allow her "new" used camper to be parked on the street under a huge splitting American Elm tree (it was good enough for the old camper). The city is supposed to fix or remove the tree. Meanwhile I can't get my camper out of the driveway without help and my DW does not understand the needs of us "men of RV science".

Quote:

If our objective is to understand how "head tilt" affects the interaction between the WDH and the TV, then, IMO, there is nothing to be gained by continuing the discussion of whether the WD bar has a "progressive spring rate".

True about the discussion, but there is knowledge to be gained by knowing the difference of spring rate. As another example, temper was mentioned as changing spring rate. According to research done by John Barca, it is possible to temper bars differently, and I assume, even from one end to the other, depending on how the heat treatment is done. Very interesting stuff.

Quote:

However, I think there is much to be gained by discussing things such as:
differences in the "orbits" of the ends of the WD bars for vertical head versus tilted head,
how differences in orbit affect WD bar loading,
and how differences in orbit and loading affect pitch and roll torque applied to the TV.


When the tow vehicle makes a turn, the bars pull the chains and the chains swing either fore or aft. Do they also describe an orbital motion? Please define what you mean by "orbits"?

Wes
...


Posted By: coolbreeze01 on 09/22/11 08:14am

Shogun wrote:

I haven't seen this one yet on this post but I love my Blue Ox Sway Pro.

Easy setup to install, easy to hook up and unhook. No sway issues, no special actions needed to back up or turn sharp.

Just works!


I agree!! Good equipment and its made in the USA


2008 Dodge 3500 With a Really Strong Tractor Motor...........
LB, SRW, 4X4, 6-Speed Auto, 3.73, Prodigy P3, Blue Ox Sway Pro........
2014 Sandsport 26FBSL


Posted By: rcase13 on 09/22/11 09:46am

Looking at the specifics of the Blue Ox and that really seems like the way to go. I really think I might upgrade to this.

Are there any negatives that anyone can think of? I've been towing with a simple friction sway control setup and this beats what I have by a mile.


2013 Jayco Redhawk 26XS



Posted By: GeoBoy on 09/03/11 08:09am

Buy an Equalizer hitch. Your hitch weight is going to be close to 1,000lbs. so you could go either with 1,000 lb. or 1,200 lb. spring bars.


Posted By: jerem0621 on 09/02/11 09:09pm

Ron Gratz wrote:

jerem0621 wrote:

I personally, am not a fan of the projected pivot point from a maneuverability stand point, same reason I prefer a TT to a Fiver.
If you are suggesting that maneuverability with a Hensley Arrow or ProPride hitch is similar to that of a Fiver, I think that is a misconception.


Hi Ron,

Thank you for pointing this out. I was specifically thinking about the physics of the pull-right hitch.

Thanks!


Posted By: LAdams on 09/02/11 09:31pm

Having towed with a Pullrite, I can confirm that backing with it offers more challenges than say the Hensley or standard hitch...

Because of the pivot point being near the rear axle differential, it responds nearly identically to a 5th wheel, which means that exaggerated steering inputs are required to position the trailer...

Trying to position a TT just a few inches to the left or right, having minimal space to the front and rear of the rig is difficult... Still, my Pullrite was just rock solid stable under ALL towing conditions...

Les


Posted By: martipr on 09/03/11 12:17am

APT wrote:

He should talk with his dealer about hitches they sell and can install for him. It takes 2-4 hours with the right tools to install and set up some of these. Not sure an RV newbie wants to do that and the PDI and buying paperwork.

Reese Straight Line and Equal-i-zer 4-point are similarly effective at about $500. Not worth saving $100 for anything else with sway control.

I like the Reese over EQ because it is quieter in operation and can be backed up with attached. It is a little more picky about being setup correctly.


Ignore the first paragraph at all costs. It is pure stupidity to talk to the dealer about which hitch. In the first place he will try to sell what ever he has or can make the most money on. Secondly they either won't know how or make the effort to set it up properly.

He should take a Reese Dual Cam Srtait Line hitch with him, have the dealer install it (guarantee it won't be set up properly) and then go to a local hitch shop for proper set up before hitting the road.

Second best would be do the same but with an Equalizer.


Old Navy Chief (AOC) Retired Aircraft Mechanic/Inspector
2007 29' 27FBV Trail Bay V Series
2007 Dodge Ram 1500 Mega Cab 5.7 V8 3.92 Rear End
Reese Strait-Line Dual Cam Hitch



Posted By: martipr on 09/03/11 12:49am

aftermath wrote:

crasster wrote:

I've NEVER once heard any complaints about Reese.


Read this one.

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/25360846.cfm


Almost assuredly improper installation.


Posted By: Ron Gratz on 09/03/11 06:41am

martipr wrote:

---It is pure stupidity to talk to the dealer about which hitch. In the first place he will try to sell what ever he has or can make the most money on.---
This might be true for some dealers, but based on my personal experiences, is not true for all dealers.

Quote:

---Secondly they either won't know how or make the effort to set it up properly.
Unless you have the TV and TT loaded approximately as they would be loaded for camping, it's very difficult for a dealer to set up the hitch properly.

Quote:

He should take a Reese Dual Cam Srtait Line hitch with him, have the dealer install it (guarantee it won't be set up properly) and then go to a local hitch shop for proper set up before hitting the road.
Same thing applies here. It's difficult for anybody to set up a hitch properly if the TV and TT are not loaded for camping.

Ron


Posted By: Slowmover on 09/05/11 04:48pm

I will put my PROPERLY installed W/D hitch and Dual Friction sway control up against ANY improperly installed W/D hitch with or without integrated sway control (Hensley, 3P, Dual-Cam, etc. etc.)


You'd "lose" in a test of the sway-eliminating type using a 3/4 or 1-T pickup. Drive one before you make these assertions. My trailer pulled fine w/o a WDH but it's flat stupid to do so when decent WDH is available. I drove with my H/A quite a few miles without the WD working (the H/A is inferior to the more finely adjusted Propride; the problem those days). The anti-sway of this type of hitch is not dependent on spring bar tension or cheesy add-ons.

Except for initial cost -- which is non-starter as annual depreciation on TV or TT is far more -- a premium hitch is cheap. Penny-wise and pound-foolish, otherwise. The distance traveled is almost irrelevant. Short trips or long, it only takes once to pay for itself.

What any video camera would show is that your TT has a great deal more side-to-side motions the hitch is struggling to correct. That it only does a fair job and is not obvious in the mirrors or through the steering says more about those components (and driver skill). Poor feedback is not a reliable measure. Friction control type is a doorstop as concerns its' best and highest value. Having to pull over and remove them from operation when the roads are wet -- when anti-sway is most needed -- tells the whole story of the "value" of the friction type.

Sort of like drum brakes: being cheap is their single virtue. A poor one in comparison to the performance lost to disc brakes, TT or TV.

.


1990 35' SILVER STREAK Sterling, 9k GVWR
2004 DODGE RAM 2WD 305/555 ISB, QC SRW LB NV-5600, 9k GVWR
Hensley Arrow; 15-cpm solo, 25-cpm towing


Posted By: Shogun on 09/05/11 06:44pm

I haven't seen this one yet on this post but I love my Blue Ox Sway Pro.

Easy setup to install, easy to hook up and unhook. No sway issues, no special actions needed to back up or turn sharp.

Just works!


Spree 318bhs. Blue Ox Sway Pro WD hitch.
Primary tow vehicle 2008 F350 V10 Crew cab.
Back-up tow vehicle 2005 4Runner V8 Limited.


Posted By: dmckee01 on 09/06/11 11:45am

I was a newby and bought our trailer at lazy days. they installed the blue ox system. We initially had it installed on my wife's Mitsubishi Montero sport and it worked perfectly! Now that I have the Dodge RAM 1500 SLT with the hemi, I dont need it as much since my truck has so much power and weighs more than my 19 foot surveyor sport TT.

http://www.blueox.us/towbars/towbars.htm

But I agree. Let the TT dealer install it. It cost us a little bit of money but you know its done right and since you're up in mountain country, ensuring its right is for peace of mind.


Posted By: martipr on 09/08/11 04:04pm

dmckee01 wrote:

I was a newby and bought our trailer at lazy days. they installed the blue ox system. We initially had it installed on my wife's Mitsubishi Montero sport and it worked perfectly! Now that I have the Dodge RAM 1500 SLT with the hemi, I dont need it as much since my truck has so much power and weighs more than my 19 foot surveyor sport TT.

http://www.blueox.us/towbars/towbars.htm

But I agree. Let the TT dealer install it. It cost us a little bit of money but you know its done right and since you're up in mountain country, ensuring its right is for peace of mind.


You must really be new if you think the dealer knows how to "do it right". Perhaps some do but they must be rare. I have had mine to 4 dealers, and I will name them: Camping World, they installed it and had no clue how to do it, Fun Time in Denton, TX, Fun Time in Cleburne, Tx and United RV in Ft. Worth, TX.
I finally got a non RV mechanic who read the instructions and did it right. It is now great.


Posted By: martipr on 09/08/11 04:14pm

Ron Gratz wrote:

martipr wrote:

---It is pure stupidity to talk to the dealer about which hitch. In the first place he will try to sell what ever he has or can make the most money on.---
This might be true for some dealers, but based on my personal experiences, is not true for all dealers.

Quote:

---Secondly they either won't know how or make the effort to set it up properly.
Unless you have the TV and TT loaded approximately as they would be loaded for camping, it's very difficult for a dealer to set up the hitch properly.

Quote:

He should take a Reese Dual Cam Srtait Line hitch with him, have the dealer install it (guarantee it won't be set up properly) and then go to a local hitch shop for proper set up before hitting the road.
Same thing applies here. It's difficult for anybody to set up a hitch properly if the TV and TT are not loaded for camping.

Ron

It might not be true for all dealers, but from my own experience and from the many, many posts on this forum they are few and far between. Why take a chance.
True it should be loaded for camping in order to set up properly, however he is not going to be loaded for camping for the trip home. At least he will be set up properly for that trip.


Posted By: jerem0621 on 09/08/11 10:37pm

'68Monaco440HP wrote:

I will put my PROPERLY installed W/D hitch and Dual Friction sway control up against ANY improperly installed W/D hitch with or without integrated sway control (Hensley, 3P, Dual-Cam, etc. etc.)


You'd "lose" in a test of the sway-eliminating type using a 3/4 or 1-T pickup. Drive one before you make these assertions. My trailer pulled fine w/o a WDH but it's flat stupid to do so when decent WDH is available. I drove with my H/A quite a few miles without the WD working (the H/A is inferior to the more finely adjusted Propride; the problem those days). The anti-sway of this type of hitch is not dependent on spring bar tension or cheesy add-ons.

Except for initial cost -- which is non-starter as annual depreciation on TV or TT is far more -- a premium hitch is cheap. Penny-wise and pound-foolish, otherwise. The distance traveled is almost irrelevant. Short trips or long, it only takes once to pay for itself.

What any video camera would show is that your TT has a great deal more side-to-side motions the hitch is struggling to correct. That it only does a fair job and is not obvious in the mirrors or through the steering says more about those components (and driver skill). Poor feedback is not a reliable measure. Friction control type is a doorstop as concerns its' best and highest value. Having to pull over and remove them from operation when the roads are wet -- when anti-sway is most needed -- tells the whole story of the "value" of the friction type.

Sort of like drum brakes: being cheap is their single virtue. A poor one in comparison to the performance lost to disc brakes, TT or TV.

.


I am honestly confused by what you are trying to correct me on...

So, my properly adjusted weight distribution hitch with "cheesy" sway control would lose against an improperly adjusted premium ...but only if I get a 3/4 or 1 ton?

Sorry, I do not have 65k bucks for a new dually, as much as I want one (and I do)(I don't even have 10k for a used one right now)... I don't have 3k for a hitch, as much as I want one (and I do)(I can't even come up with 500 for an equal-i-zer right now). I CAN NOT tow with a 3/4 or 1 ton truck because I can't afford one right now.

Yup, I have rear drum brakes too...(Cheap is a VERY important virtue for some people)

In jest, should I just sell my TT and my Truck because I am so inferior to those who have means to buy more expensive things?

I am doing the best I can with the means I have. With my family we do not have much disposable income for things such as a new Diesel Dually payment or a HaHa. We worked, scraped, and saved for our truck and trailer.(so we wouldn't owe for them)

My friction sway control is NOT cheesy, It is the best I can afford right now. I AM much more safe and have a proper set up compared to a lot of rigs that I see out there on the interstate. My trailer and truck feel very stable towing now with the dual friction sway control compared to no sway control.

Sorry, my jacked up old stuff doesn't measure up to your standards.

I am quite content with my set up.

Cheers.

Jeremiah

* This post was edited 09/08/11 10:57pm by jerem0621 *


Posted By: Huntindog on 09/09/11 03:13am

APT wrote:

He should talk with his dealer about hitches they sell and can install for him. It takes 2-4 hours with the right tools to install and set up some of these. Not sure an RV newbie wants to do that and the PDI and buying paperwork.

Reese Straight Line and Equal-i-zer 4-point are similarly effective at about $500. Not worth saving $100 for anything else with sway control.

I like the Reese over EQ because it is quieter in operation and can be backed up with attached. It is a little more picky about being setup correctly.


????????????? You don't disconnect anything to back up with the Equal-i-zer.


Huntindog
2010 Palomino Sabre 30BHDS
TWO bathrooms...No waiting!
MICHELIN XPS RIBS LRE
2011 Silverado Big Dually 3500 4x4 CC D/A
EQUALIZER Hitch
100% BOONDOCKING
Check out Rusty and her pups at www.bluecollarbrittanys.com



Posted By: Huntindog on 09/09/11 03:19am

APT wrote:

jerem0621 wrote:


Reese DC...rely on FRICTION of some type to reduce or eliminate sway.


I do not agree with this. While there is some friction, the primary design element is more spring force on the bars from the bend/angle on the cam lobe.

Otherwise, a great post!


It's friction mainly. The calculations have been done and posted in the past. The cam lobes are NOT the main source of the anti sway function.


Posted By: Ron Gratz on 09/23/11 05:11am

Wes Tausend wrote:

When the tow vehicle makes a turn, the bars pull the chains and the chains swing either fore or aft. Do they also describe an orbital motion? Please define what you mean by "orbits"?
When I refer to the "orbits" of the ends of the WD bars for vertical head versus tilted head, I am talking about the path followed by the rear end of the WD bar as the bar pivots on its trunnion.

For a "vertical" head, the orbit would be a circle in a horizontal plane. The diameter of the circle would be the effective length of the WD bar (distance from trunnion center to chain attachment).

For a "tilted" head, the orbit would be a circle in a plane having a pitch-axis rotation with respect to the hitch. The tilt of the orbit would cause the end of an unloaded WD bar to be at different elevations depending on the degree of swing (pivoting) of the bar. For example, Andy Thomson's article referred to a bar which is 4" off the ground when the TT is straight behind the TV. When the bar itself is straight behind the TV (rotation of about 25 deg), the end of the bar is 3" off the ground. When the head was vertical, the end of the bar was a constant 11" off the ground.

Of course, when a WD bar is being used, it is not unloaded. Also, the end of the bar remains at essentially a fixed height off the ground controlled by the height of the A-frame. An unloaded bar can be assumed to be straight, and a loaded bar will have some curvature. The amount of curvature depends on the amount of load. A tilted bar will experience maximum load when the bar is straight behind the TV. The load on the tilted bar will decrease as the bar swings away from the straight-behind position. The load on a bar which has a vertical pivot axis will not change as the bar swings.

The degree of swing determines the position of the end of the bar in its orbit. The longitudinal distance from the trunnions to the end of the bar is the length of the lever arm which applies pitch-axis torque to the hitch. This distance decreases as swing increases. The lateral distance from the TV's centerline to the end of the bar is the length of the lever arm which applies roll-axis torque to the hitch.

A tilted trunnion axis causes the orbit to be slightly elliptical when projected onto a horizontal plane. The major axis of the ellipse is the same as for a vertical trunnion axis. The minor axis of the ellipse is equal to the bar length times the cosine of the tilt angle. The maximum change in height of the end of an unloaded bar is equal to the bar length times the sine of the tilt angle.

The differences in "orbit" -- primarily the differences in height of the end of an unloaded bar -- are what determine the difference in effect of a tilted head versus a vertical head.

Ron


Posted By: Ron Gratz on 09/23/11 05:52am

Wes Tausend wrote:

---It is important to me to be able to understand not just what, but precisely why things happen as they do, so I will tuck an analysis of John's results away for another day when I have more time and just start a new thread.
Wes, I think that's an excellent idea. You might want to put the thread in the Towing Forum since that's a "Technical Resources" forum.

It seems these discussions always get tacked onto some existing thread. A separate thread might have a very small audience, but at least our esotericism would have a home of its own.

Perhaps you could get Andy Thomson to join the disucssion.

Ron

* This post was edited 09/23/11 06:03am by Ron Gratz *


Posted By: sbrettell on 09/23/11 10:46am

Both issues need to consider the tongue weightnof your unit. Talk to the dealer.


SteveB
In Maryland


Posted By: jasoncw on 09/22/11 10:51am

I read about the SwayPro, and it does sound pretty good. I don't have any experience with it though. And it looks to be about $100 more than the EQ or DC.


Posted By: Shogun on 09/22/11 03:37pm

Seeing what others in the campground go through to hook up their trailers the extra cost is worth it to me.

As an aside I have been able to transfer the unit between 3 trailers with simple bar upgrades for much less than the cost of a whole hitch.


Posted By: Wes Tausend on 09/23/11 06:53pm

Ron Gratz wrote:

Wes Tausend wrote:

---It is important to me to be able to understand not just what, but precisely why things happen as they do, so I will tuck an analysis of John's results away for another day when I have more time and just start a new thread.
Wes, I think that's an excellent idea. You might want to put the thread in the Towing Forum since that's a "Technical Resources" forum.

It seems these discussions always get tacked onto some existing thread. A separate thread might have a very small audience, but at least our esotericism would have a home of its own.

Perhaps you could get Andy Thomson to join the disucssion.

Ron


Real physics often getting "tacked on" to more casual discussion is the absolute truth, Ron.
But I suppose any "Best Hitch" thread best resides in the towing forum too. We are lucky our esteemed moderator, Les Adams is often one that likes to follow such intricate "deviate", but wandering, "how-it-works" discussions. I'm sure John Barca and a few others do, too, when they have the time.

In the interest of enlightenment, it seems like my duty to take my own "rig-turning" WD bar static load measurements, and do it in such a simple way that it not only makes sense applying the results directly to Andy's original idea, but is easily, and quickly, repeatable for those that regard hollow quazi-logical speculation be taken with a grain of salt. The proof of the pudding is in the eating.

I'll have to ponder the "orbit" description, in your post above, a bit more. My reading comprehension doesn't yet follow all you have stated. In particular, I'm not sure where our stationary frame of reference is in the scenario. As only one possible frame of reference example, the truck and trailer both may be moving on the surface of "stationary" earth to contibute to an orbit.

When the hitch assembly is connected, I prefer to visualise the TT a my stationary frame of reference, and I haven't yet realised where the end of the bar can follow much of anything but a fore-and-aft motion (excluding trunnion bearing friction), in relation to the "stationary" TT A-frame tongue, when the shank is swung from side-to-side on the "stationary" vertical ball/coupler axis.

But it is true there would be a section of a slight elipse described if one were to disconnect the end chain and yet keep the tilted-axis bar level with the groundplane, all while rotating the bar in it's tilted trunnion bearing. I'm not sure we need trigonometry to visualise this. Is trig needed in this manner for calculation of the precise roll forces?

I agree, it would be interesting to see Andy Thomson make an appearance on this forum. He might be more likely to do so would I be able to demonstrate his idea were correct... or would he then find it still necessary?

My 10:00 AM call to work has arrived a little late. I'm off to Glendive.

Wes
...


Posted By: mefly2 on 02/23/12 09:45am

Be sure and ask where the hitch is manufactured and with steel from where. Let's help our US economy wherever we can. We are very happy with the Equalizer Hitch built right here in the USA ... Utah specifically.


>>> mefly2 <<<
AirStream Flying Cloud / EQ hitch
Ram Crew 6.7 Cummins HO Diesel


Posted By: Uncle Wiggly on 02/26/12 11:00am

Ron G and Wes, regarding tilted head of hitch:

Clearly, the only way the Andy Thompson theory works is if spring bars have progressive rates.

So my question is, "How could a tapered bar NOT be progressive?"

Regarding Mr. Baca's experiment, I am very good at experimental procedure and I cannot get consistency with my Sherline scale. Maybe my scale is defective, but there seems to be significant internal friction and that yields +/- 25 lbs even when in the center of my 1000# scale. According to his description Mr. Baca took his readings while RELAXING the tension. My experience is that relaxing gives different readings from compressing. Also, any side vector introduced into the procedure affects the results significantly, and since there are pivot points either at the TT axle or the floor jack base, there ARE side vectors.

Although I have not recorded detailed data (I am now re-setting and calibrating my WD hitch) it appears that my EZ-Lift 800# bars (tapered, trunnion) are exponential in their progressive increase, at least in the range of adjustment needed to equalize my rig. The difference between 2 links loose and 3 loose is monumental.


2011 Lance 2285, 2010 Mercedes-Benz ML350 Turbodiesel


Posted By: Huntindog on 02/26/12 01:05pm

I gonna dispute the "Friction controls are worthless" comments.

I have used them in the past and would have no problem using one again.

Friction controls are the oldest design out there, and there arte more of them than any other. It is a very simple system. So simple that even when not setup right,,,it still works to some extent. I truly can be a hook up and tow type of deal.
Most of wht I see are not setup right, but theier owners are happy with the improvement it gave them.

While there are some advantages of the higher end hitches, setup is the key with them.

Most that use higher end hitches are more into setup, so they are OK with dialing a hitch in.


Posted By: Ron Gratz on 02/26/12 02:51pm

Uncle Wiggly wrote:

So my question is, "How could a tapered bar NOT be progressive?"
Before responding to your question, I need to know -- How do you define "progressive"?

Quote:

Although I have not recorded detailed data (I am now re-setting and calibrating my WD hitch) it appears that my EZ-Lift 800# bars (tapered, trunnion) are exponential in their progressive increase, at least in the range of adjustment needed to equalize my rig. The difference between 2 links loose and 3 loose is monumental.
Please post details of your experimental procedure and your data and analysis. Then we will have a good basis for a meaningful discussion.

Ron


Posted By: Uncle Wiggly on 02/27/12 09:38pm

Ron Gratz wrote:

How do you define "progressive"?
Ron

Increasing in a nonlinear fashion.

It'll be a while before I have anything meaningful to post. My weeks tend to be 80 hours.
As I said, I haven't been able to obtain repeatable data with my Sherline, but the seemingly large difference between two links loose and three ought to be measurable.

There may be too many variables to consider without constraining the pieces. If that's what it takes, I sure won't get to it until fall....
Mike


Posted By: Wes Tausend on 02/29/12 10:20pm

Uncle Wiggly wrote:

Ron Gratz wrote:

How do you define "progressive"?
Ron

Increasing in a nonlinear fashion.

It'll be a while before I have anything meaningful to post. My weeks tend to be 80 hours.
As I said, I haven't been able to obtain repeatable data with my Sherline, but the seemingly large difference between two links loose and three ought to be measurable.

There may be too many variables to consider without constraining the pieces. If that's what it takes, I sure won't get to it until fall....
Mike


Glad to see you join this discussion, Mike. I don't think it is easy for many people to visualize Andy's theory, and it's nice to see an understanding and interest in such things besides Ron and I.

When Ron and I were talking of progressive spring loading, I took it to mean more tension for each additional successive unit of delection. In other words, the first deflected inch might take 10 pounds (total of 10), the second inch might take 11 more pounds (total of 21) etc. This should occur until the stage of plastic deformation is reached. My intuition dictates that a tapered "equalizer" bar should behave this way, but I could be wrong. However, if I remember right, one of the engineering reference formulas Ron provided also seemed to indicate a progressive rate to me, as I think I said in an above post.

I still have some intentions to do some weight measurements later this spring, but it will require getting my former camper out of winter storage and making measurements on the most level parking lot that I can find. I'll have to make do with an ordinary bath scale set up either in a lever/ratio apparatus for out of range scale weights, or direct for lesser weights within the bath scale range.

For lesser weights, I may be able to place a small hydraulic jack on the bath scale and lift the "chain end" of the bar in both straight ahead and turned towing positions, with a tilted head of course. If Andy's theory works, the ends of the bars may change tension as he describes between a turn and straight ahead position. All I need measure, is to lift enough tension to note a slight chain slack. When the slack just occurs, the scale should indicate present bar tension.

I note your legitimate concern with the Sherline shaft friction. If my ordinary jack suffers a slight "stiction", I believe it should not matter as the combined resistance of hydraulic pressure and piston friction should always weight the scale equally well regardless of pressure/friction ratio.

Wes
...


Posted By: Slowmover on 03/02/12 06:12pm

Inland RV of Corona, CA made the following addition to their website a year or so back about spring bars:

The Hitch Torsion Bar Story

.


Posted By: Ron Gratz on 03/03/12 08:23am

Wes Tausend wrote:

---However, if I remember right, one of the engineering reference formulas Ron provided also seemed to indicate a progressive rate to me, as I think I said in an above post.
Wes,

The tapered cantilever beam equation which I referenced in this post does NOT show a "progressive rate".

The equation shows that the ratio of tip load divided by tip deflection is constant for a given beam . And, that is a definition for a linear relationship.

Ron


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