Torsion Bars on WD Sway hitches

TerryandKim wrote:

The Equal-i-zer and every other friction hitch has zero self centering properties. They are dampeners.

Then the WD doesn't re-centre the trailer, it just slows the
off-center and the trailer brings itself back to centre ... maybe better said, the trailer comes back to centre due to the force of the TV pulling it forward?

Yes to all of this!

The Equal-i-zer and every other friction hitch has zero self centering properties. They are dampeners.

Then the WD doesn't re-centre the trailer, it just slows the
off-center and the trailer brings itself back to centre ... maybe better said, the trailer comes back to centre due to the force of the TV pulling it forward?

The Equal-i-zer and every other friction hitch has zero self centering properties. They are dampeners.

Thanks!

Jeremiah

What he means is with a friction control, once the trailer is angled away from straight behind the TV, the friction device also resists allowing the combo to return to a straight ahead position. So it restricts movement both directions.
The DC has ever increasing resistance to the trailer moving off center and then it uses that spring tension to help return it to center

Okay, thanks, so this is what I understand then. The dual cam has tension such that when it forces the trailer back to centre it actually brings it off centre slightly on the other side, then back to centre. With other friction devices (ie: equalizer) they will bring it back (slower?) to the centre. Hmmmmmm

I really don't think the guy knows what a torsion bar is either.

Lynnmor wrote:
The word "torsion" is not even in the Reese catalog. I wouldn't pay much attention to someone that doesn't know what a torsion bar is.

This is true, but the author of this article has been selling Airstreams and installing hitches for the better part of 4 or 5 decades. Many of the oldtimers who were around back when the first EZ-Lifts were sold refer to these bars as torsion bars.

I'm pretty sure that torsion is the correct term for the action that a WD hitch places on a TV, which is where that term came from.

Thanks!

Jeremiah

The word "torsion" is not even in the Reese catalog. I wouldn't pay much attention to someone that doesn't know what a torsion bar is.

No, I don't think thats the message.
What he means is with a friction control, once the trailer is angled away from straight behind the TV, the friction device also resists allowing the combo to return to a straight ahead position. So it restricts movement both directions.
The DC has ever increasing resistance to the trailer moving off center and then it uses that spring tension to help return it to center.

FWIW, I've had both and feel the Dual Cam works much better than the other style that use a friction material.
However, I also think there are some other technologies available that look very good. They use springs built into the head or some other leverage to do the same job.

In a turn the cam rides up and down the crooks of the WD bar. The cam arms do not move and are in a fairly fixed point relative to the length of the chain. So when WD bars move in a turn or in a sway event the amount of pressure increases on the cam arm.

In theory this force should tend to make the hitch settle back into the at rest position at the top of the crook.

You can see the forces with a simple experiment. Take a rubber band and stretch it between two fingers, Now take your other hand and grab the middle of the bands that are stretched.

now, pull the rubber band from the middle. You will feel resistance from the band trying to overcome the pulling force from the middle of the band.

This is similar to the force that is at work in the DC. The cam arm is your fingers grabbing the rubber band in the middle... the rubber band is the WD bar under tension from simple WD. As the band (WD bar) moves it increases the force and the WD arm wants, tries to return to at center.

Hope this helps,

Thanks!

Jeremiah