friction vs. dual cam sway bars

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genenkay

New member
Joined
Nov 28, 2005
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2
Location
McComb, Mississippi
Are the dual cam sway bars better than friction or just different. On my maiden voyage without a sway bar (28', 5000 lb. trailer, 1/2 ton pickup) I didn't experience much wind but whenever a semi rig passed me I experienced my truck moving left towards the semi. I think this results from the air he is pushing shoving my trailer to the right which presses the hitch to the left. Will either type sway bar prevent this or is one better than the other for this?

Gene Lueg
 

John From Detroit

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Apr 12, 2005
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24,765
Location
Davison Michigan
The tendency of a vehicle to move toward a semi when one passes you is due to aerodynamics. The air around the semi is moving faster (due to being pushed out of the way) and faster moving air has a LOWER pressure than slower or still air (Which is what is on the OTHER side of your vehicle) thus... One could say... Passing semi's sucks

But it's the partial vaccume that pulls your truck toward the semi, not pressure on the trailer
 

Kenneth

Well-known member
Joined
Nov 21, 2005
Posts
438
Gene,

I have never used the cam type ,but I would never pull another TT without a sway bar. It virtually eliminates the "sway" from passing trucks.
 

Carl L

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Mar 14, 2005
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7,239
Location
west Los Angeles
I like the Dual Cams from the standpoint that when you tension the spring bars correctly, the cams are tensioned correctly.  No separate adjustment needed.  The Reese Products website says:

The advantage of the dual cam system is its ability to forestall sway in addition to sway resistance. It works to hold down the start of swaying activity while at the same time allowing free and easy vehicle and trailer interaction. Another advantage of the dual cam system is that it?s installed on the trailer and therefore doesn?t require adjustment every time the towing vehicle and trailer are hooked up, unless hitch weight or tow vehicle loading are changed.

Since Reese sells both the Dual Cam and a friction damping system I would tend to give them some credence in the matter.  A deciding point might be the tongue weight of your trailer -- dual cam setups like heavy tongue weight, more than 500 lbs for sure.

By the way, I have used a Dual Cam setup for some 15 years on two TTs and a boat trailer.  The same setup, transferred from rig to rig. 



 

Lou Schneider

Site Team
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Mar 14, 2005
Posts
10,889
Dual Cams do like hitch weight - they work by positioning the equalizing weight bars in a saddle that's attached to the trailer A-frame.? When the trailer is straight ahead, the indentations in the end of the equalizing bars are centered on the humps (or cams) in the saddle.? If the trailer turns to one side or the other, the bars ride up on the sides of the cams and the downward pressure of the arms against the side of the cams tries to make the trailer return to a straight-ahead position.

The important point to the dual-cam arrangement is the hitch opposes movement away from a straight ahead position, and aids in returning the tow vehicle and trailer to a straight line.? The tighter you crank the weight distribution arms, the more self-centering force the hitch exerts, so it works best with trailers that have a lot of hitch weight.

You're right - it's the trailer pressing sideways (to the right) against the hitch that makes the front of your rig turn left.? ?The blast of air from the truck's bow wave hits the front half of the trailer, pushing it to the right.? ?At the same time the partial vacuum is pulling the rear of the trailer towards the truck.? Both of these combine to make the front of the trailer lean to the right.? This pushes the hitch to the right, the tow vehicle pivots around it's rear axle and it's front end moves left.? The longer the distance between the tow vehicle's rear axle and the hitch, the more leverage the trailer can exert on the rig's direction of travel.? ?That's why 5th wheels are inherently more stable without needing any kind of sway control devices - their pivot point is directly over the tow vehicle's rear axle.? Side forces from the trailer press directly against the rear axle so they don't have any leverage to affect the direction of the tow vehicle.

A friction bar sway control simply dampens the side to side rotation around the hitch.? ?When you tighten down on the sway bar, you're stiffening the joint between the tow vehicle and the trailer.? ?The hitch opposes the trailer moving off-axis, but once the car and trailer are at an angle, it also resists them getting back into a straight line by the same amount of force.? ?This is why the manufacturers recommend loosening up the sway control if the road is wet, or if there's anything thing else that might reduce traction.? In an extreme case, if the car's front tires lose traction at the beginning of a turn, the sway bar will prevent the rig from turning.? Or if the front wheels lose traction in the middle of a turn, the car and trailer can stay locked into an angle and will continue turning instead of straightening back out.

I like the dual-cam.? I use it to tow an Artic Fox 26X with a 3/4 ton pickup.? Loaded the Arctic Fox weighs about 8500 lbs and has 800-900 lbs of hitch weight.? The dual cam works extremely well for me - the trailer feels almost like a 5th wheel.? Passing trucks and side winds have little or no effect on the rig.

But again, it's anti-sway effectiveness is proportional to the amount of hitch weight - or more precisely, the amount of countering force the equalizing bars are exerting against the hitch.
 
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