Reese cam sways

[clancy_boy]

Originally Posted by ticki2

It looks like a weight distributing bar without the dual cam . The dual cam is what gives you most of the sway control.

I stand corrected - you are right - it looks like an older Reese WD bar set I sent to ALANSD not the newer sway control bars.

[Silverhobby]

I have towed for more than 24 years with the Reese system. I too believe that when I least expect it, I may need it the most. I hope that I will never have to find out how truly effective any of my safety equipment is.

[2airishuman]

hi lipets...

i'm in the camp that suggests proper safety equipment increases the margin...

when the fuzz hits the fan...

so i offer you this thread to read....

http://www.airforums.com/forum...i+sway+control

big tv; little trailer....

still bad things happen

also, on the way to the international in salem this year,

and officer (vp?) from the indiana region lost it in wyoming...

rippley road, cross winds and a semi in the next lane...

he was towing a 30/31 with an excursion...

many years of towing and airstream'n

and still lost it and jack knifed...

so if your trips are all short and free of traffic, wind, flats and road hazards....

i'll take the safety equipment anyday.

cheers
2air'

[koltys]

I am the owner of the Bronco/Overlander combo that spilled in 2004, and I don't mind it being mentioned at all. Here are some details about the incident. The setup was a 1995 Ford Bronco, "Bam Bam," with "Betty," a 1974 27' International Overlander, load-distribution bars and a friction-type anti-sway bar.

This same rig had previously made it across the country and back twice, which allowed me to grow a bit complacent. The driver at the time of the spill was not a confident driver. In her first five minutes behind the wheel, going less than 50 mph, the wash from a passing truck triggered a tail-wag that resulted in the trailer swinging around in front of the truck before dragging us into the ditch. It hadn't occurred to me to train and drill the drivers on using the electronic brake controller to arrest severe sway.

The Bronco, all the truck I could afford at the time, was not an ideal tow vehicle. It was geared wrong, such that the overdrive had to be locked out, or the transmission would hunt excessively between 3rd and overdrive. Needless to say, in 3rd, the mileage was miserable. The wheelbase was also too short for my Overlander. The combination had a tendency to sway, but confident drivers, male and female, had always been able to keep it tamed, with the help of the anti-sway bar.

As one person here has pointed out, at the time of the spill, the front end was riding high. I was aware of this, but allowed a jammed chain link on the load-distribution bars to prevent me from correcting the situation. Big mistake.

Fortunately, nobody was injured in the incident. After the initial violent occillation, the tipping over and sliding to a stop was surprisingly gentle. I hope never to experience it again. I consider it my fault, and not that of the driver, although it took a lot of convincing to get her to believe this. I would have been a lot less calm about the whole thing if it wasn't insured with an agent that I trusted.

Lessons learned:
- Use a tow vehicle with a long enough wheel base.
- Load properly and not excessively.
- Set load-distribution bars correctly.
- Stick with confident drivers.
- Practice, practice, practice reaching for the brake controller.
- Always carry trailer insurance.
- 4 butts sitting in a 3-person rented-truck cab for 2 1/2 days is a difficult, but not impossible test of friendship.

My current rig, a Chevy Tahoe with a 1964 19' Globetrotter, "Mabel," tows like a dream without even a hint of sway, even with no anti-sway bar.

[Safari Tim]

Hey guys, just to plug the show and maybe help out a little here.

The Thanksgiving episode of theVAP we talk with hitch expert Bob Tooker from Reese. We talk about weight distribution, sway control, brake controllers, etc....

Just a heads up!

[47WeeWind]

Originally Posted by koltys

My current rig, a Chevy Tahoe with a 1964 19' Globetrotter, "Mabel," tows like a dream without even a hint of sway, even with no anti-sway bar.

Hi Koltys:

My '64 Glober Trotter also tows like an obedient dream, which I attribute in large part to the rearward position of the single axle, quite a bit aft of the trailer centerline. That rearward position is necessary due to the black water tank being at the tail end and many appliances being grouped in the center or rear half of the trailer. To my mind, the readward axle position casues the trailer to track better and dampen sway quicker than would a more forward or centered position, which may amplify or prolong sway once induced (there being more tail to wag).

Having a 1992 Dodge 3/4 ton extended cab diesel truck helps (when it says "follow me" the trailer listens), but the trailer just seems particularly well laid out for stable towing. Oh, the virtues of vintage!

[Chuck]

I noticed the same thing looking at the pics, before reading the subsequent comments: the hitch isn't setup properly, truck "nose high" and trailer "nose-low".

I had a "dual-cam" moment on a recent outing, when someone slammed their brakes on in front of me on the highway. I had to slam the brakes on, as well, and started to swerve to avoid an impact. The car in front of me moved out of the way at the last second, and I turned the steering wheel to stop the swerve. In that split second as the rig was turning, I could feel the trailer turn (starting to "jack-knife") on the ball as the rig turned, and when I straightened, the sensation was like a *snap* back to straight and locked. It really did feel like a "jack-knife"...only in a good way. you know how when you open the blade on a jack knife and when it gets close to being fully extended, it snaps into place? like that. Without the dual cam, I imagine that this kind of quick swerving maneuver at that speed (50-60-ish) would set up a really severe tail-wagging situation, but the DC just snapped everything right back to straight-as-an-arrow.
Without the dc, there may not have been any consequence in this situation...the truck is certainly adequate for the load. but the trailer didn't "seek" a straight line, like you would imagine occuring in the absence of any type of sway control, swaying back and forth a little less with each oscillation, until equilibriam was re-established. Like I said, it just "snapped" back into place.

[thecatsandi]

Dual cams do nothing for you when the road is slick with packed snow or ice either. Speaking from personal experience. The setup is quite robust though. THe ball deformed and bent. the head, shank, and sway bars were un-damaged.

[Mike Lewis]

We have a dual cam reese also and for the most part pleased, however just reciently ordered a Hensley Arrow for the following reasons. The sway control of a dual cam is dependent upon the presure applyed by the spring bars on the cams. The more pressure, the more it resist hinging at the ball. In our application our tow vehicle,{2004 HD Chev Duramax} is sprung in the rear enough that very little spring tension is needed to level the combo, thus lessing the resistance to turn and sway. I probably could have reduced the rear suspention of the TV by removing a spring leaf or 2 but that would have effected the use of the truck when not towing. The Hensley sway control is not dependent upon the load applyed to the baars to control sway, thus our reason for change. This is not to be critical of the Dual Cam system at all but to point out that even the very best of products must have the proper application.---Pieman

[ALANSD]

what we don't know is the speed the first driver was doing. we have had folks here state they tow at 75 plus miles per. Gotta wonder how smart that is as well.

[2airishuman]

Originally Posted by Mike Lewis

We just reciently ordered a Hensley Arrow .---Pieman

hey pieman welcome to the fold...

you are gonna love it!

hopefully you will join us now in this thread....

http://www.airforums.com/forum...de-26279.html

and share your experience with the transitiion, tips and tricks and so on....

cheers
2air'

[Chuck]

Originally Posted by Mike Lewis

The sway control of a dual cam is dependent upon the presure applyed by the spring bars on the cams.

yes, but that is why they have different sized bars. for a more heavily sprung tow vehicle, you use lighter spring bars, which will function the same with less pressure on the cams.

[TomW]

Originally Posted by chuck

...for a more heavily sprung tow vehicle, you use lighter spring bars, which will function the same with less pressure on the cams.

Lighter weight rating spring bars are preferred for heavily sprung tow vehicles because they will allow the Airstream & tow vehicle to flex independantly over something like a pothole in the road.

But any weight spring bar, when adjusted to make the tow vehicle level will put the same amount of pressure on the cams. The force exerted on the cams is what is making the tow vehicle level.

Tom

[2airishuman]

ok cam heads...

i got no cams, so i know from zip...

and would not know the difference between a reese's hitch and a peanut butter cup...

but my interpretation of (inlandandy) bar selection is that the bars need an inch? or more of flex for the antisway function to fully engage...

with a big truck and little trailer the lesser rated bars must flex more to transfer a given mass....and sway control is maximized.

while sway control is reduced with heavier rated bars that are not flexed enough...

have i got that right?

cam heads..

2air'

[Mike Lewis]

Chuck--- I agree with the part of your statment concerning sizing bars for the spring rate of the tow vehicle. I think we also agree that the more pressure on the cams the more sway control we have. Correct bar sizing is important but the size of the bars is not changed so as to increase or decreased cam pressure but more to help control the ride of the tow vehicle and trailer. To heavy bars cause harsh TV ride but cam presure remains the same as a weaker bar assuming both bars lift the same weight the same distance. Here's my reasoning. If you find fault with it please reply. An illustration:: a wheelbarrow with 2 inch diameter handles is loaded and lifted while measuring the load at the end of the handles. Now if we change handles to 1 inch diameter then lift the same load and measure it again you will find it takes the same amount to lift it as it did the larger handles. The difference is the smaller handles flex more. The presure applied at the hands remains the same. If you roll both wheelbarrows over bumps you would find the one with the smaller bars would "jar" the user less but the energy needed to lift remains the same. While not perfect,the wheelbarrow illustrates similar geometry as the spring bars when they are loaded. As I understand it the cam load is in direct proportion the the amount the bars have to lift the front of the trailer and the rear of the TV to a level attitude. I am not implying that sizing of bars is not important. It is very much so but the purpose is not to increase or decrease cam load.---respectfully ---Pieman

[TomW]

Originally Posted by 2airishuman

i got no cams, so i know from zip...
...but my interpretation of (inlandandy) bar selection is that the bars need an inch? or more of flex for the antisway function to fully engage...

From your wonderful (...although...sometimes...hard to read.. ) insight on other topics, I find that difficult to believe.

You're right - Andy say, [paraphrased] "Crank the bars up! The more the better They're tested to five inches bend with no damage."

Materials have a property called the spring constant. For simplicity, let's say 1000 pound bars have a spring constant of 200 pounds per inch deflection. Bend the bar 1 inch and you get 200 pounds of force on the cam. Applying the same general line of reasoning, a 550 pound spring bar would have a lower spring constant on the order of 110 ppi.

Adjusting a 550 pound bar to deflect three inches would give you 330 pounds of force. The 1000 pound bar would only have to be deflected 1.65 inches to yield the same amount of force.

Tom

[Chuck]

yes, I believe you are all correct, and I mis-spoke. not "pressure", but "flex". I don't think it has to do with the load on the cams, so much, but when that spring bar is "flexed", it becomes a horizontal spring. <--> (pushing fore and aft). the "up/down" force, like in the wheelbarrow example, is only doing the weight transferrance. the right combination of pressure and flex in the bars puts the cams and saddles in an orientation that will allow the fore/aft spring action to absorb the force of the a-frame as it tries to swing out and move toward the rear of the tow vehicle. the resistance on the bars pushes the a-frame back into a straight orientation. If the spring bars don't deflect, because they either aren't tightly attached, or are just too stiff, they won't bend when forward force is applied; something will either break, or the saddles will just pop off of the cams, and you got nuthin'. Because of the shape of the cams/saddles, movement initiated by the truck allows the saddle to slide off the cam; but movement initiated by the trailer ("sway") causes the 2 to lock, resisting further movement.

that's my story, and I'm sticking to it.

[Mike Lewis]

Originally Posted by TomW

From your wonderful (...although...sometimes...hard to read.. ) insight on other topics, I find that difficult to believe.

You're right - Andy say, [paraphrased] "Crank the bars up! The more the better They're tested to five inches bend with no damage."

Materials have a property called the spring constant. For simplicity, let's say 1000 pound bars have a spring constant of 200 pounds per inch deflection. Bend the bar 1 inch and you get 200 pounds of force on the cam. Applying the same general line of reasoning, a 550 pound spring bar would have a lower spring constant on the order of 110 ppi.

Adjusting a 550 pound bar to deflect three inches would give you 330 pounds of force. The 1000 pound bar would only have to be deflected 1.65 inches to yield the same amount of force.

Tom

Tom-- I agree completely but if it takes,for example 200lbs of upward lift on the end of a bars to bring the vehicles to a level attitude the difference between the large and small bar with 200 lbs of force on them is simply more deflection in the smaller bar. As I see it 200 lbs is 200 lbs no matter what size bar is being used. ----pieman

[TomW]

Originally Posted by Mike Lewis

Tom-- I agree completely...

Originally Posted by Mike Lewis

...but ...

Originally Posted by Mike Lewis

... As I see it 200 lbs is 200 lbs no matter what size bar is being used.

Yes, you are correct. That is the point I was hoping to make.

Tom

[Mike Lewis]

Originally Posted by chuck

yes, I believe you are all correct, and I mis-spoke. not "pressure", but "flex". I don't think it has to do with the load on the cams, so much, but when that spring bar is "flexed", it becomes a horizontal spring. <--> (pushing fore and aft). the "up/down" force, like in the wheelbarrow example, is only doing the weight transferrance. the right combination of pressure and flex in the bars puts the cams and saddles in an orientation that will allow the fore/aft spring action to absorb the force of the a-frame as it tries to swing out and move toward the rear of the tow vehicle. the resistance on the bars pushes the a-frame back into a straight orientation. If the spring bars don't deflect, because they either aren't tightly attached, or are just too stiff, they won't bend when forward force is applied; something will either break, or the saddles will just pop off of the cams, and you got nuthin'. Because of the shape of the cams/saddles, movement initiated by the truck allows the saddle to slide off the cam; but movement initiated by the trailer ("sway") causes the 2 to lock, resisting further movement.

that's my story, and I'm sticking to it.

I agree with you Geometeeee---pieman