# What Is Sway?



## campmg (Dec 24, 2005)

I've posted similar questions but not sure I get it yet. Is sway

1. The front of the travel trailer pushing the rear of the TV?
2. The TV and Trailer being blown as one unit to the side when big rigs blow by?
3. Both?

The Equalizer seemd to keep the Yukon and 25RSS together but we got pushed a bit. Maybe I just need LT tires and not sure what we experienced would be better with the Hensley.


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## Oregon_Camper (Sep 13, 2004)

Let's see if this helps...

Sway:
Fishtailing action of the trailer caused by external forces that set the trailerâ€™s mass into a lateral motion. The trailerâ€™s wheels will serve as the axis/pivot point for the trailer.

Sway Bar:
A device connected from the A-frame of the trailer to the hitchball platform of the tow vehicle in order to reduce sway.

Sway Controller:
Device designed to damp the swaying action of a trailer, either through a friction system or a cam action system that slows and absorbs the pivotal articulating action between tow vehicle and trailer.

Now that you have that information, its easy to tell that sway can start in many ways.

1) Stong gust of crosswinds (natural wind)
2) Wind caused someone passing from the rear of the trailer (typically a larger one)
3) Quick/Rapid lane changes.
4) Poor trailer design (not Outbacks







) Ie...too much weight behind the trailers axles causing the tongue weight to be less than 10% of the trailers weight it has a natural tendency to sway.
5) Incorrect tire inflation
6) Improper weight distribution hitch adjustments
7) No sway control on the trailer
8) Descending inclines
9) Excessive Towing speeds
10) Tow vehicle not properly matched for the trailer (we know this topic all to well)
11) Improper loading of trailer....overloading and poor weight distribution

Hope this helps...


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## CamperAndy (Aug 26, 2004)

12) Too short of a wheel base on the TV for the trailer exaggerates the sway.


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## campntn (Feb 20, 2005)

Sway, (verb)
English: what Jessica Simpson does in the Pizza hut commercials when she comes in the door carrying a pizza, wearin those boots.








Mark


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## hatcityhosehauler (Feb 13, 2004)

Actually, for a very good explaination on sway, request the free DVD from Hensley. It is of course a commercial for their hitch, but they give a very good explaination of what sway is, and some of it's causes, along with some demonstration video's.

But for a quicker, and more general answer to your question,



> 1. The front of the travel trailer pushing the rear of the TV?


Partially. The ball hitch acts like a fulcrum, and the weight of the trailer, can and will try to move the tow vehicle. This is why there is a corrolation between wheel base of the TV, and the length of trailer.



> 2. The TV and Trailer being blown as one unit to the side when big rigs blow by?


I think everyone will experience this, no matter what hitch they have. I've experienced it without the trailer hooked up. As long as everything is moving as one, and not independently, then things should remain stable.



> The Equalizer seemd to keep the Yukon and 25RSS together but we got pushed a bit. Maybe I just need LT tires and not sure what we experienced would be better with the Hensley.


 LT tires would certainly help. With your TV's wheelbase, you are pushing the edge on the tail wagging the dog issue (your question #1). The rule of thumb, and this is only a rule of thumb is 20' of trailer length for the first 110" of tow vehicle wheel base, then one additional foot of trailer for each additional 4" of WB after that. As you get to the stiffer 3/4 and 1 ton susupensions, and longer wheel bases, this becomes less of an isssue.

Hope this helps.

Tim


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## Thor (Apr 7, 2004)

Outstanding info
















Thor


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## Herbicidal (Aug 29, 2003)

campntn said:


> Sway, (verb)
> English: what Jessica Simpson does in the Pizza hut commercials when she comes in the door carrying a pizza, wearin those boots.
> 
> 
> ...


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## Morrowmd (Feb 22, 2005)

You will know sway if you are ever unlucky enough to experience it. It gives you butterflies down in the pit of your stomach.

I have never experienced it with the OB, but had a bad case of it once pulling the popup with the Astro van. Seems I had too much weight in the rear of the popup and it made for a scary trip down the Interstate.

A little pushing and moving is normal, hopefully you will never experience swaying!


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## CamperAndy (Aug 26, 2004)

campntn said:


> Sway, (verb)
> English: what Jessica Simpson does in the Pizza hut commercials when she comes in the door carrying a pizza, wearin those boots.
> 
> 
> ...


or is that Sashay? Looks better on her then on your TV/TT combo.


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## tdvffjohn (Mar 10, 2005)

CamperAndy said:


> campntn said:
> 
> 
> > Sway, (verb)
> ...


Does not matter what its called


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## Oregon_Camper (Sep 13, 2004)

The heck with the Pizza Hut commercial...have you seen her MTV video.


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## cookie9933 (Feb 26, 2005)

Oregon_Camper said:


> Sway:
> Fishtailing action of the trailer caused by external forces that set the trailerâ€™s mass into a lateral motion. The trailerâ€™s wheels will serve as the axis/pivot point for the trailer.


I respectfully disagree that the trailer's axles are the pivot point. IMO, the pivot point is the trailer hitch/ball. The trailer swings in an arc around the ball, but as it does so it also exerts a push to the rear of the TV from side to side. Whether that push actually moves the rear of the TV sideways depends on several factors such as the severity of sway, the weight of the TV's rear end and corresponding lateral traction, TV tires, etc.

If the TV's rear end does get moved (pushed sideways or fishtails or whatever you want to call it), all TV vehicle dynamics are affected. In other words, you will have to enter the correct steering inputs to keep on the road. Many say that applying the TT brakes only can bring sway under control. This is probably true if sway is not too severe. Depending on the severity of sway, you will succeed or not. This is why sway control is so important.....you want to prevent sway from getting started in the first place.

Bill


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## kjp1969 (Apr 25, 2004)

It's number one. Picture yourself driving down the road with no sway control, minding your own business. A cross wind (or gust from a truck, etc) comes up and hits you broadside from the right. Since your trailer has more surface area than your TV, it catches more of that wind, and is pushed more to the left than your TV. Since the front of the trailer is connected to the TV by the trailer ball, and the TV continues to drive straight, the wind causes the trailer tries to rotate about its wheels, counterclockwise by a couple of degrees. The trailer and TV pivot about the hitch ball, so when the front of your trailer sways left, (rotates counterclockwise) the rear of your TV rotates the opposite way (clockwise).

Then, because you're still traveling in a straight line, your whole rig wants to straighten out, so your trailer pivots back about the ball clockwise like a pendulum, pulling the back end of the TV with it, past straight by a few degrees in the opposite direction. Of course, then the trailer catches the same wind, and rotates counterclockwise again, perhaps more than before because its got more inertia this time. Unchecked, this whole mess builds and builds until you're sliding sideways down the highway.

You can see how the size of the trailer makes a huge difference- the bigger it is, the more wind it catches. The longer it is, the greater the leverage against the trailer ball.

You can also see how the profile, weight, wheelbase, suspension and rear tires of the tow vehicle make a tremendous difference in how much the movement of the trailer affects the TV. Folks with F350 duallys often say "I've never ever had trailer sway." Well duh, the rear of your TV is like a rock, of course it doesn't move around.

Friction sway control damps the movements with, well, friction. The Reese dual cam does something else, I have no idea what. A fifth wheel (or hensley or trailrite for that matter) eliminate the problem by moving the pivot point forward from aft of the rear bumper to directly over (or in front of) the rear axle. That way, forces from the trailer aren't pulling the truck around by its suspension, but are more directly transferred to the tires, where they simply push the TT/TV left or right as a straight unit. You still get pushed by the wind (that's inevitable) but only as if you were driving a straight truck, not an articulated TV/TT combo.

People often say that you should accelerate or hit the trailer brakes during sway- I can see how this should work, but of course in my case it didn't- we ended up losing the TV and TT (luckily no injuries) By the way, take it from someone who knows: the whole left-right-left thing can happen fast. Really fast, as in, don't have a cup of coffee in your hand, because you won't be able to put it back in the cup holder fast enough to react.

(Wow, what a rant, eh?) In closing: don't panic. Set your rig up carefully, build in a margin of safety when choosing your TV/TT combo. Be realistic with your equipment and experience level. And if you encounter sway, react properly, stop and figure out what caused it, then fix it. I don't think any sway is acceptable, and we didn't want a 1-ton truck for a daily driver, so we bought a Hensley. You might get along just fine with your own very different setup- I see big trailers being pulled without weight distribution or sway control all the time with no apparent problems. Just be responsible, be aware and be safe!

Kevin P.


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## Morrowmd (Feb 22, 2005)

kjp1969 said:


> (Wow, what a rant, eh?)Â
> 
> Kevin P.
> [snapback]90635[/snapback]​


Kevin, when *you* talk about sway I will listen carefully to every word you say!

-Matt


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## PDX_Doug (Nov 16, 2004)

I think Kevin hit this one right on the head. Great 'white paper' Kevin!








And, of course, who can argue with someone that has truely 'been there - done that'.

Kevin makes one point that is maybe lost in all the rest of the story, that is worth reflecting on. That is that the TV/TT are going to move when hit by a gust of wind. be it caused by a pasing truck, or actual wind, that air has to go somewhere, and if it is strong enough, it is going to move you out of it's way. It's all about HOW it moves you!









Happy Trails,
Doug


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## stapless (Feb 20, 2005)

Sway = white knuckles







, wet pants







, and a funny smell that you blame on the dog







!!

scott


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## nascarcamper (Jan 27, 2005)

S-swinging W-way A-across Y-yellowline


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## mountainlady56 (Feb 13, 2006)

campntn said:


> Sway, (verb)
> English: what Jessica Simpson does in the Pizza hut commercials when she comes in the door carrying a pizza, wearin those boots.
> 
> 
> ...


Typical male, typical male......need I say more?








Darlene action


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