Sway Control really needed ???

DiskDoctr wrote:
All this technical jargon to prove how intelligent everyone is and how they are 'immune' to sway.

I just hope no one's over-confidence (dare I say arrogance?) gets them or anyone else hurt or worse :O

Not immune to sway. If I hadn't taken time to correctly adjust the hitch. I'd have sway too. Has nothing to do with arrogance. Has Everything to do with setting up correctly. If your trailer has sway. You have a problem. Somewhere something is not right. Find it, Fix it. Your trailer should not sway. It was designed NOT to. There is a lot more to it than dropping it on the ball , and taking off. A few hours of work setting up the hitch is time well spent. Unless you like living dangerously. I don't. I like worry free, relaxed driving. No white knuckles here. That is no way to drive..
I just hope folks driving around with sway. Doesn't hurt anyone.

All this technical jargon to prove how intelligent everyone is and how they are 'immune' to sway.

I just hope no one's over-confidence (dare I say arrogance?) gets them or anyone else hurt or worse :O

2012Coleman wrote:

Sway is caused by an unstable oscillatory (under damped) mechanical system

This is not the cause of sway, it is the definition of it. When that system is not in motion, there is no sway. Something must cause the oscillation. Sway can be caused by a number of forces:

Towing Speed - The speed at which you decide to tow your trailer may be the single greatest factor in controlling trailer sway. Any speeds greater than 45mph tend to allow almost any trailer to begin to sway. With traffic traveling at much greater speeds it isn't practical, and most of the time illegal, to travel at a speed that will control trailer sway. (would like to hear from people who experience sway at speeds lower than 45 - I don't)

High Winds
Gusting Winds

Bow Wave - A bow wave is a wind produced by a large semi-truck, box truck or van pushing its way through the air on the highway. This wind travels around the truck and down the sides creating a wind disturbance in the adjacent lanes. This wind disturbance creates a sudden high to low pressure in the air traveling down the side of your trailer. The bow wave, as with the other wind disturbances, creates a tow angle by pushing the trailer and pivoting it on the hitch ball. The bow wave produces a "sucking" feeling in some combinations that feels like the entire tow combination is being pulled into the other lane. (this is exactly what I experience and yes it is sway)

Bad Roads
Downhill Travel
Poor Trailer Design
Improper Loading
Poor Weight Distribution Hitch Adjustment

A properly setup one will not sway at ANY speed. If yours is swaying at 45 MPH. You need to park it. If the bow wave of passing trucks is pushing you in to another lane. You need to adjust your balance, and WDH. You should feel it, but that is all. It should not move you around. It is not sway. As I said earlier. Sway is when the trailer starts moving around all on it's own, in normal driving, with no outside forces pushing it around.

And it should not sway at any speed with out sway control. As mentioned above. NEVER hide a sway problem under a sway control band aid. Adjust your trailer to the point that is does NOT sway at any speed, and then, and only then add sway control.

Sway control is only for those times when sway is induced by maneuvering in an emergency situation, like dodging a hazard in the road, or losing a tire. You should not need it any other time.

Case in point. My trailer has -o- sway at any speed. I don't need sway control to drive down the road. Trucks don't bother me, either when passing me, or me passing them. However I do use sway control. You never know when someone will cut you off, a Deer will run in front of you, or a tire will blow. That is what sway control is for.

Sway is caused by an unstable oscillatory (under damped) mechanical system

This is not the cause of sway, it is the definition of it. When that system is not in motion, there is no sway. Something must cause the oscillation. Sway can be caused by a number of forces:

Towing Speed - The speed at which you decide to tow your trailer may be the single greatest factor in controlling trailer sway. Any speeds greater than 45mph tend to allow almost any trailer to begin to sway. With traffic traveling at much greater speeds it isn't practical, and most of the time illegal, to travel at a speed that will control trailer sway. (would like to hear from people who experience sway at speeds lower than 45 - I don't)

High Winds
Gusting Winds

Bow Wave - A bow wave is a wind produced by a large semi-truck, box truck or van pushing its way through the air on the highway. This wind travels around the truck and down the sides creating a wind disturbance in the adjacent lanes. This wind disturbance creates a sudden high to low pressure in the air traveling down the side of your trailer. The bow wave, as with the other wind disturbances, creates a tow angle by pushing the trailer and pivoting it on the hitch ball. The bow wave produces a "sucking" feeling in some combinations that feels like the entire tow combination is being pulled into the other lane. (this is exactly what I experience and yes it is sway)

Bad Roads
Downhill Travel
Poor Trailer Design
Improper Loading
Poor Weight Distribution Hitch Adjustment

Terryallan wrote:

69 Avion wrote:
I think that folks need to consider the difference between "sway" and an "unstable" trailer. Sway with RVs is usually caused by cross winds or passing big rigs.

An unstable trailer can have a few causes, one of which is improper loading with a lack of sufficient tongue weight. If this occurs bad enough the trailer will be unstable.

.

In truth. the bow wave from a truck or cross winds is NOT sway.

Sway is when the trailer starts fish tailing all on it's own at ANY speed, in normal driving. Bad balance, too little tongue weight, and poor hitch setup will cause that.

A properly setup trailer will not sway.

As for the wind. Your pulling a big wide sail. The wind is gonna move it, and as for the trucks. You will always feel them go by, They even feel each other go by. It just shouldn't be enough to bother you.

Well said. Your response is technically sound and to the point. Sway is caused by an unstable oscillatory (under damped) mechanical system almost always caused by too little tongue weight. An unstable system can achieve critical damping and become a stable system by adding resistance such has a friction sway bar that functions much like a shock absorber does on a spring suspension. A marginally stable system can go into uncontrolled oscillation when triggered by an external force such as cross wind or effects of a large passing semi.

Dick

Terryallan wrote:

69 Avion wrote:
I think that folks need to consider the difference between "sway" and an "unstable" trailer. Sway with RVs is usually caused by cross winds or passing big rigs.

An unstable trailer can have a few causes, one of which is improper loading with a lack of sufficient tongue weight. If this occurs bad enough the trailer will be unstable.

.

In truth. the bow wave from a truck or cross winds is NOT sway.

Sway is when the trailer starts fish tailing all on it's own at ANY speed, in normal driving. Bad balance, too little tongue weight, and poor hitch setup will cause that.

A properly setup trailer will not sway.

As for the wind. Your pulling a big wide sail. The wind is gonna move it, and as for the trucks. You will always feel them go by, They even feel each other go by. It just shouldn't be enough to bother you.

I think that we may be saying the same thing, just using different terminology. The "sway control" should help with the effects of wind and sudden pressure changes against your trailer. That is why I call it "sway". The uncontollable, unstable trailer caused by too low of tongue weight or an imporperly loaded trailer (or improper manufacturing) shouldn't be masked by sway control. If the trailer is unstable, the trailer should be fixed by means other than a sway control system. Maybe some folks actually try to mask an unstable trailer with "sway control", but I would never consider that as an option since it isn't fixing the problem. Can you imagine a sway control failure at 65 mph? I have seen an unstable triple axle trailer whip a Ford Excursion around like it was a rag doll at about 45 mph. If that happened suddenly at 65 mph, I don't think a driver could recover fast enough to keep from tearing up something or causing a wreck.

69 Avion wrote:
I think that folks need to consider the difference between "sway" and an "unstable" trailer. Sway with RVs is usually caused by cross winds or passing big rigs.

An unstable trailer can have a few causes, one of which is improper loading with a lack of sufficient tongue weight. If this occurs bad enough the trailer will be unstable.

.

In truth. the bow wave from a truck or cross winds is NOT sway.

Sway is when the trailer starts fish tailing all on it's own at ANY speed, in normal driving. Bad balance, too little tongue weight, and poor hitch setup will cause that.

A properly setup trailer will not sway.

As for the wind. Your pulling a big wide sail. The wind is gonna move it, and as for the trucks. You will always feel them go by, They even feel each other go by. It just shouldn't be enough to bother you.

21ft htt and tow with a 2500 sub. No sway needed.

JCR-1 wrote:
OK ..I installed the friction bar as per instructions.. How tight does this have to be when going down the highway? Thanks!

The sway bar is factory adjusted for most conditions. Turn the handle as far as it will go and then back if off to be parellel witht he trailer frame. This handle is an "on/off" device and is not supposed to be used to adjust the amount of tension.

The small bolt located below the bar is the adjustment bolt. It should only be turned in 1/4 increments when adjusting as a little goes a long way.

The above statements are taken almost word for word from the insructions of most of the common sway bars.
Barney

OK ..I installed the friction bar as per instructions.. How tight does this have to be when going down the highway? Thanks!