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barts · 10-23-2011, 12:48 PM

Quote:

Originally Posted by Kosm1o

Perhaps it would be helpful if some of the more experienced and knowledgible on the subject, would actualy list some causes of the kind of sway that causes a loss of control. Then , maybe, we could see the benefits of having a sway control hitch.

The problem is that uncontrolled oscillations of the trailer can have a variety of contributing causes, and not all accidents blamed on sway are actually the result of trailer oscillations, leading to much confusion and many arguments :-).

Number one factor contributing to trailer sway is incorrect loading; either insufficient tongue weight or high polar moments (all the weight at the ends of the trailer) can cause sway all by themselves. As far as I know, no anti-sway system will prevent sway if the trailer is sufficiently incorrectly loaded, although they may prevent problems in marginal cases.

Some other contributing factors (I won't try to rank these):

* Excessive speed... speed shows up in most math models of trailer dynamics; the higher the speed both the more likely sway is to happen and the more violent it can be.

* Incorrect driver reactions; some drivers attempt to correct for trailer motion; depending on the dynamics of the combined TV & trailer system this can actually make things worse. If the tow vehicle reacts to trailer motion, this can require conscious restraint on the part of the driver. Note that math models of trailer behavior generally DO NOT include the driver as part of the dynamic system; I believe that understanding some of the more complex aspects of vehicle behavior requires modeling the driver.

* Tow vehicle suspensions (including tires) with insufficient sideways stiffness. will cause the tow vehicle to appear to wiggle around; this will increase the odds that the driver does the wrong thing.

* While not really trailer sway, I think that some accidents blamed on sway are actually caused by incorrectly adjusted trailer brakes... if the trailer is too lightly braked, it can push the tow vehicle. If the tow vehicle doesn't have working ABS on the rear wheels the rig can start to jack knife; if the driver then releases the brakes suddenly vehicles can overturn. Over braked trailers can cause worse problems; locked up trailer wheels generate no side forces and less braking than the TV, so a jack knife is very likely... and if the driver releases the brakes in reaction the trailer can overturn.

- Bart

Inland RV Center, In · 10-23-2011, 01:26 PM

Bart.

I agree with your comments above.

We also felt very storngly, that disorientation played a hand in loss of control.

Typically, when a brain says go that way, or turn the steering wheel that way, to get out of a sway, it's exactly backwards, since the "seat of our pants" takes over instead of our eye sight.

Our "inner ear" (cochlea) plays a very important part in that, granted to a small degree, but in fact does have a negative effect.

Motion, combined with some speed, can and does, cause many seemingly impossible things to the human brain.

Andy

Lumatic · 10-23-2011, 02:10 PM

I would add road conditions to Bart's excellent list: dirt, gravel, uneven surface, snow and ice, wet pavement.

Also, weather, especially wind.

And speaking of wind, the pressure wave from passing larger vehicles.

SteveH · 10-23-2011, 02:38 PM

Quote:

Originally Posted by boondockdad

I started a poll here:
http://www.airforums.com/forums/f464...ml#post1062686

Polls are no more than popularity surveys, and what is most popular is frequently the cheapest, not the best.

boondockdad · 10-23-2011, 05:06 PM

Quote:

Originally Posted by SteveH

Polls are no more than popularity surveys, and what is most popular is frequently the cheapest, not the best.

The only thing cheap, has been your 2 cents on the topic.
None of this is scientific. Play along, why don't you?

Kosm1o · 10-23-2011, 05:08 PM

So, of the causes of sway, which of them will an anti-sway hitch likely help? And how much is it likely to help? Some, it appears, don't give the Equilizer hitch very good marks for the friction anti-sway it has. Yet many on this forum use them with great success. I am guessing that anti-sway is more about proper set-up and safe-driving and maybe less about the hitch. I ask this because I have many miles behind the wheel pulling many types of trailers without incident. Now I have an Airstream that came with an Equilizer. I trust my driving skills so why would or should I consider a different one?

Diesel1 · 10-23-2011, 05:14 PM

Thank you Bart. Well spoken. Adios, John

ROBERT CROSS · 10-23-2011, 05:18 PM

Quote:

Originally Posted by Kosm1o

So, of the causes of sway, which of them will an anti-sway hitch likely help? And how much is it likely to help? Some, it appears, don't give the Equilizer hitch very good marks for the friction anti-sway it has. Yet many on this forum use them with great success. I am guessing that anti-sway is more about proper set-up and safe-driving and maybe less about the hitch. I ask this because I have many miles behind the wheel pulling many types of trailers without incident. Now I have an Airstream that came with an Equilizer. I trust my driving skills so why would or should I consider a different one?

If your comfortable with what you have....why change?

I've never experienced sway, regardless the cause, with the Hensley set-up properly.

Bob

Diesel1 · 10-23-2011, 05:30 PM

Come come Bob, thats not valid. I have never experianced sway regardless the cause either, and I have nothing but a bare ball on my rig. And as ignorant & uneducated as some seem to think I am I know the fact that it hasn't happened with my Airstream doesn't mean it can't.
I have experianced violent glad to be alive sway in the distant past of my youth. That was caused by a very light tongue on a trailer that I had loaded. I quickly began to study the cause of my near demise & have modified my actions accordingly. Adios, John

Lumatic · 10-23-2011, 06:02 PM

Quote:

Originally Posted by Kosm1o

So, of the causes of sway, which of them will an anti-sway hitch likely help?

Sway is sway. How much does it help? I would rather not find myself in a out of control situation to find out. Cheap insurance.

SteveH · 10-23-2011, 06:04 PM

Quote:

Originally Posted by finalcutjoe

The only thing cheap, has been your 2 cents on the topic.
None of this is scientific. Play along, why don't you?

I am "playing along"...I voted. But still don't like polls because in this instance, for example, even if everyone votes, means nothing about what hitch performs the best, or worst, just what is most popular.

It's almost as meaningful as asking people what is the best car made at a Chevrolet convention.

And sorry, I guess the word "cheap" was inappropriate. I should have said most plentiful.

r carl · 10-23-2011, 06:08 PM

Quote:

Originally Posted by Zigidachs

My dad always said that those who discus politics, money, and religion will eventually make the worst of enemies from the best of friends.

Add motor oil to that list.

Mike Leary · 10-23-2011, 06:13 PM

Were I to have a trailer, especially an AS, I'd find the best of the best sway bars. We've followed some "trailers" that were moving around so much, that we pulled over so we would not have to see it go over.

perryg114 · 10-23-2011, 06:26 PM

Well we just made it back from FL. We had no sway control going down and any speeds over 60 got me concerned. I used the friction sway control on the way back and it really helped. I was able to run 65 to 70MPH without feeling like I was going to get into trouble. I do think the friction system made rut handling worse. I think a lot of the problem with stability is that they make even trucks with very twichy sports car handling. It takes almost no movement of the steeing wheel to put you in another lane. The trailer is going to react to that quick movement with sway. Any type of jerk of the wheel and then a correction to get you back where you were is going to get that trailer swaying. Personally, I think trucks with very slow steering response at high speeds would be a good thing. Also making them return to center so they will tend to stay straight unless forced to turn would be good. My excursion and all large Ford trucks I have driven have no road feel. If you are not paying attention 100% of the time you will drift out of your lane. I think part of this is the twin I-Beam system Ford uses on the front of their trucks.

Perry

Mike Leary · 10-23-2011, 07:14 PM

Quote:

Originally Posted by perryg114

I think part of this is the twin I-Beam system Ford uses on the front of their trucks.

You might do some checking to see when Ford quit making "twin-I-Beams"; it was a while ago, a long while ago.

SteveH · 10-23-2011, 07:26 PM

I know this thread is about sway control, but the subject of truck steering has come up, and there is a relevance.

The one thing that I DO NOT like about my GMC 3/4 ton truck is the steering. It uses a steering box like days of old and has some play. Like Perry states it allows the truck to try to climb out of the 18 wheeler rutted roads, either one side or the other, and I am constantly working to prevent it from happening.

My pervious truck, a GMC 12 ton, had rack and pinion steering, and there was zero play, and so the truck drove like a sports car....very accurate. Why can't the manufacturers put good modern steering systems on 3/4 ton trucks?

pmclemore · 10-23-2011, 07:27 PM

My theory is that I want "forgiveness". I want to be excused for inattention. And for adverse conditions. And for going too fast downhill, but I wasn't really going too fast, but something happened that made me wish that I was going much slower. I want to be able to slow quickly without the trailer trying to pass me and making my recovery efforts futile.

Not too much to ask. I bought a factory-refurbished Hensley because I believe in the buy-it-once theory. And because I bent a bracket on my old-style Reese dual cam and I don't know exactly when. But I think it was in Flaming Gorge the previous evening.

So - do you need sway control? I don't know. Suit yourself. I know I believed in it enough to buy it and would do it again tomorrow. Hensley or Propride, that is. Nothing else.

I also believe in the theory that your teenager won't believe how little control they have until they are scared by their first accident (or near accident). If they survive that, they will be much safer drivers as a result.

Pat

perryg114 · 10-23-2011, 07:41 PM

Well it is against my religion to drive anything newer than 10yrs old. So 10 yrs old is new to me. I don't do the new trucks that you have to fill them with pee pee to get them to run.

Perry

Quote:

Originally Posted by Mike Leary

You might do some checking to see when Ford quit making "twin-I-Beams"; it was a while ago, a long while ago.

boondockdad · 10-24-2011, 04:23 PM

I wonder how many folks posting here, actually have experience with the various hitch types.

I happen to have experience with 4 of the 5 types.

Here's what's left of my friction anti-sway bar setup. 2500 RAM megacab (the last pic is the location of the rollover... yes, it was uphill):

Here's my Equal-I-zer setup:

The Hensley Arrow on my 2008 Classic:

and just the ball on my '65 Ambassador:

Friction bars are useless.
The rollover was the first (and last) instance of any sway with that rig- at all. At 65 mph, it was instantaneous- like cracking a whip, and uncontrollable.

Equal-I-zer was adequate, but felt much the same as my friction bar.

There is no substitute for the Hensley. The most solid, balanced towing experience, ever.

Nothin' but ball works well enough for the much lighter Ambassador (not even torsion bars)- but then, we don't take that one over 55mph... and once the refit is finished, and we're treking long distances, I'll install a ProPride.