Sway control and backing up

[BDK]

I just bought a friction sway control (Draw-Tite) for our new pop up and I have heard that you shouldn't back up with the sway control attached.  I understand turning too tight can cause harm, but what difference is there between moving forward or backward?  Anyone get into trouble with tight turns (going forward....er uh backward?)

[tlhdoc]

I just bought a friction sway control (Draw-Tite) for our new pop up and I have heard that you shouldn't back up with the sway control attached. I understand turning too tight can cause harm, but what difference is there between moving forward or backward? Anyone get into trouble with tight turns (going forward....er uh backward?)

You heard correct.  Do not back up with the friction sway attached.  Something will bend.  A friend of mine tried backing with his sway bar on and damaged his hitch.

[wavery]

I just bought a friction sway control (Draw-Tite) for our new pop up and I have heard that you shouldn't back up with the sway control attached.  I understand turning too tight can cause harm, but what difference is there between moving forward or backward?  Anyone get into trouble with tight turns (going forward....er uh backward?)

Think of the sway bar as a tow rope. It is meant for pulling only. If you push with it (back-up) it will bend.

[mike4947]

When going foward the two pieces of the control pull apart, so the worst that would happen in they would seperate. In backing the pieces telescope into each other and can bottom out. When that happens something has to give.

It's better to take the time to disconnect it every time. You never know when you're going to need to jack knife the trailer to get into a spot and trust me that's just when you forget about the sway control...LOL

[griffsmom]

We were told to always disconnect ours before backing up--even if going straight back. For the few extra seconds it takes to remove the sway bar, why take a chance?

[AustinBoston]

I just bought a friction sway control (Draw-Tite) for our new pop up and I have heard that you shouldn't back up with the sway control attached.  I understand turning too tight can cause harm, but what difference is there between moving forward or backward?  Anyone get into trouble with tight turns (going forward....er uh backward?)

We don't use a sway bar any more (our WDH has a sway mechanism built-in), but we did for our first season.  Despite what has been said here, there is no real difference between going forward and going backwards with a sway bar.

BUT...there may be a perceptual difference.  Depending on your backing style, a turn may look like less of a turn when backing than when going forward.  And, because of the way turns happen when backing, a damage-causing turn will happen much faster and much easier when backing than going forward.

You have to remove the sway bar.  Why not remove it before backing?  For a variety of reasons (especially safety), the driver really should get out and look at the space they are backing into before doing so.  It only takes a moment to remove the sway bar at the same time.

Austin

[wavery]

We don't use a sway bar any more (our WDH has a sway mechanism built-in), but we did for our first season.  Despite what has been said here, there is no real difference between going forward and going backwards with a sway bar.

BUT...there may be a perceptual difference.  Depending on your backing style, a turn may look like less of a turn when backing than when going forward.  And, because of the way turns happen when backing, a damage-causing turn will happen much faster and much easier when backing than going forward.

You have to remove the sway bar.  Why not remove it before backing?  For a variety of reasons (especially safety), the driver really should get out and look at the space they are backing into before doing so.  It only takes a moment to remove the sway bar at the same time.

Austin

My brother forgot to remove his sway bar, last year, while backing his TT into a spot. The sway bar bent bad enough that it coudn't be used again.

[chasd60]

You can jack knife backing up, never seen it done while DRIVING forward. That is the reason to disconnect prior to backing up.

That perceptual difference is more than perceptual.

[AustinBoston]

Think of the sway bar as a tow rope. It is meant for pulling only. If you push with it (back-up) it will bend.

The purpose of a sway bar is to dampen unwanted side-to-side movements of the trailer.  In order to do so, it applies a resistive force to all turns, but does nothing during straight-line movement.  All sway control devices, whether a sway bar, dual-cam sway control, or a few bizzare other types I have seen, work this way.

A sway bar is nothing but a linear brake.  The braking action is only relevant when something (changing the angle between the tow vehicle and trailer is the only thing unless it is installed incorrectly) causes it to slide in & out.  When moving forward or backward in a straight line, all of the energy is transferred between the vehicles through the hitch ball, none throuth the sway bar.

The sway bar (if it works) applies exactly the same forces when towing forward as "towing" backwards - zero.  

The only time a sway bar applies any force at all is during a change in the angle between the tow vehicle and the trailer.  If the angle does not change, (such as would happen when going in a straight line or going around in consistent circles), then the sway bar applies no force at all in either direction.

The following assumes the sway bar is mounted on the right (passenger) side and moving forward:

* When the tow vehicle turns to the right, the sway bar contracts and pushes the tow vehicle during the process.
* When it straightens again, it pulls on the tow vehicle with the same forces.

* When the tow vehicle turns to the left, the sway bar lengthens and pulls the tow vehicle during the process.
* When it straightens again, it pushes on the tow vehicle with the same forces.

* These forces serve to dampen sway beacause they apply the forces to the right side of the hitch.

(Reverse left/right above if your sway bar is mounted on the left/drivers side.)

If the sway bar did not work equally in either direction, it would only be able to dampen sway in one direction.

My brother forgot to remove his sway bar, last year, while backing his TT into a spot. The sway bar bent bad enough that it coudn't be used again.

Either:

1) it made contact with the hitch during a turn or
2) it over-extended during a turn and could not properly contract.
3) it over-contracted during a turn and was damaged as a result.

In any case, it was damaged by a turn, perhaps a turn while backing, but not by backing up itself.

BTW, either of these is much more likely while backing than while going forward.

Austin

[AustinBoston]

You can jack knife backing up, never seen it done while DRIVING forward. That is the reason to disconnect prior to backing up.

That perceptual difference is more than perceptual.

That depends on the relationship between tow vehicle wheelbase and hitch-to-trailer axle length.  With shorter tow vehicles and longer trailers, it is easy to jacknife going forward.  I do it twice every time we hook up when attaching the WDH.  I swing to a point that would most definitely have damaged my old sway bar.

Austin

[GeneF]

Friendly owner of a campground was guiding me onto the site.  This was with my Sienna and Mesa.  I left the sway bar on.  I noticed the owner kind of disappeared after he had me jacknifed.

After getting into the site, I noticed a nice dent in the bumper that the sway bar had put there.  Sway bar was fine.

[AustinBoston]

Friendly owner of a campground was guiding me onto the site.  This was with my Sienna and Mesa.  I left the sway bar on.  I noticed the owner kind of disappeared after he had me jacknifed.

After getting into the site, I noticed a nice dent in the bumper that the sway bar had put there.  Sway bar was fine.

Maybe that's the problem...tougher $100 swaybars so that $1500 bumpers get wrecked instead of the $100 swaybar!  :yikes:

Austin

[fritz_monroe]

In any case, it was damaged by a turn, perhaps a turn while backing, but not by backing up itself.

That's like saying that falling off a building doesn't kill you, it's the sudden stop at the bottom. :eyecrazy:

Yes, you are correct, however, when moving forward, the weight of the trailer causes it to move back in line with the TV because the trailer is being pulled.  But when backing, the normal action of the trailer is to move to one side or the other, not to stay in line with the TV.  That's the reason that backing up does no apply the same forces to the anti-sway device as it is moving forward.

[BDK]

The purpose of a sway bar is to dampen unwanted side-to-side movements of the trailer.  In order to do so, it applies a resistive force to all turns, but does nothing during straight-line movement.  All sway control devices, whether a sway bar, dual-cam sway control, or a few bizzare other types I have seen, work this way.

A sway bar is nothing but a linear brake.  The braking action is only relevant when something (changing the angle between the tow vehicle and trailer is the only thing unless it is installed incorrectly) causes it to slide in & out.  When moving forward or backward in a straight line, all of the energy is transferred between the vehicles through the hitch ball, none throuth the sway bar.

The sway bar (if it works) applies exactly the same forces when towing forward as "towing" backwards - zero.  

The only time a sway bar applies any force at all is during a change in the angle between the tow vehicle and the trailer.  If the angle does not change, (such as would happen when going in a straight line or going around in consistent circles), then the sway bar applies no force at all in either direction.

The following assumes the sway bar is mounted on the right (passenger) side and moving forward:

* When the tow vehicle turns to the right, the sway bar contracts and pushes the tow vehicle during the process.
* When it straightens again, it pulls on the tow vehicle with the same forces.

* When the tow vehicle turns to the left, the sway bar lengthens and pulls the tow vehicle during the process.
* When it straightens again, it pushes on the tow vehicle with the same forces.

* These forces serve to dampen sway beacause they apply the forces to the right side of the hitch.

(Reverse left/right above if your sway bar is mounted on the left/drivers side.)

If the sway bar did not work equally in either direction, it would only be able to dampen sway in one direction.



Either:

1) it made contact with the hitch during a turn or
2) it over-extended during a turn and could not properly contract.
3) it over-contracted during a turn and was damaged as a result.

In any case, it was damaged by a turn, perhaps a turn while backing, but not by backing up itself.

BTW, either of these is much more likely while backing than while going forward.

Austin

Austin,

I'll be taking the anti sway bar off when backing, but what is your opinion of a direct right or left turn 90Deg...say turning into a side street?  Do they handle that OK?  I suppose I just need to watch the first time to be sure.

[AustinBoston]

Austin,

I'll be taking the anti sway bar off when backing, but what is your opinion of a direct right or left turn 90Deg...say turning into a side street?  Do they handle that OK?  I suppose I just need to watch the first time to be sure.

Generally, you should be turning wider with a trailer than you might without.  The trailer always tracks inside the turn from the tow vehicle, so if the tow vehicle just misses the curb, the trailer will probably hop the curb.

If you turn wide enough so that the trailer does not go places it should not, you should be fine.  While I have seen places where it might be a problem, those would be places I would not be taking a trailer.  (The narrow streets of South Boston come to mind).

Austin