Sway. Before, during and after.

[ROBERT CROSS]

Originally Posted by DCPAS

Thank you for your correction. I should have said the tire experts who post here, Tireman9 and Capriracer. For what it is worth, the Goodyear chart notes that industry standards for load and inflation are in the process of being revised and its tables are as of June 16, 2017. At some time, not sure when, Airstream went to 80psi on its trailer tires.

When it appeared on the sidewall possibly?

FWIW.... AS even recommended max on the GYM's that were on our AS from new.
We followed that 'recommendation' along with the max speed limit, 13yrs one self inflicted curb rash failure.

Bob
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[BayouBiker]

Originally Posted by jcl

Life, liberty, and the pursuit of trailer sway?

All people have the right to put other road users in danger?

Some trailer dealers and hitch installers and those who insist on overloading their midsized SUVs with too large, and too heavy trailers seem to think so. As for me, I noted that the responsibility for a proper set-up rests with the driver.

[Vitaver]

Originally Posted by smithcreek

Yes and weighing your rig is the most important step you can take in getting the weight distribution hitch set up correctly. You need to make three passes on the scale. First with nothing but your tow vehicle. Second with the trailer attached but no weight distribution applied. And third with the trailer attached and weight distribution applied.

You will then compare the weight on all three axles from each pass to determine if you have not exceeded any of their limits and if you have applied the correct amount of weight distribution to achieve the best weight on each axle. It's not a difficult process, but can take a little while to understand and get right. Best thing to do is go to the scales, get the three weights and start a thread here on the forum where you post the results and get people that have more experience with CAT scales to take a look, explain what's going on and give suggestions.

Thank you, I absolutely will.

[drbrick]

First - our TV weights more that our AS, Second - we use a Reese dual cam antisway system and the TV come with antisway assist, Third - we never drive faster that 65mph, fourth - we never overload the AS. We have never experienced sway in the years we have been towing.

[jimfa440]

Originally Posted by Vitaver

Sway, how to prevent it, what to do when it gets past comfort level and what to do immediately if results in disaster is a topic that certainly was addressed in many threads and will be a major endeavor to collect them all, so I hope we can start a discussion strictly limited to the 3 items at the top. Hard to imagine anyone towing, no matter for how long (12 years in my case), is not preoccupied with any of the three topics, so let’s give it a try to help each other and newbies.

Sway happens... It does result on catastrophe many times a year. It is an important topic no matter what TV, TT or hitch is used yet our collective experience and research may help us all. I‘ll post one for each following this, to initiate the conversation on this chat. Thanks to all who take an interest and chose to contribute.

Checking tyre pressures, safety brake connected at both ends and 7 way connector providing power to the TT are understood.

Sway can be controlled but it can also be prevented. I've been pulling trailers for over 50 years and finally bit the bullet and bought a ProPride hitch. Totally prevents sway.

[BayouBiker]

Propride hitches have very very strong damping factors. Nothing can totally prevent sway. I am certain I can demonstrate sway on a combination with a propride hitch. They are marvels, but they can't do miracles.

[Vitaver]

Originally Posted by drbrick

First - our TV weights more that our AS, Second - we use a Reese dual cam antisway system and the TV come with antisway assist, Third - we never drive faster that 65mph, fourth - we never overload the AS. We have never experienced sway in the years we have been towing.

Do you leave the TV anti sway assist on while using the hitch’s similar system, both working combined/in tandem? There is literature suggesting to disable one or the other. Very interested in your experience.

[Vitaver]

On I70 east-bound Denver to Dillon, CO there is a reservoir that is frozen and at any time one can see from the highway that there are 10 or more vehicles (cars, SUVs, pickup trucks) driving through cones. I wonder if that is just for fun, competition or learning/practice for driving on ice. I might be interested on the last, especially if they have instructors. Anyone knows?

[Vitaver]

PP3, does it leave room behind the TV to open the Leer door up, and back ‘door’ down, maybe extend the truck’s sliding bed? Anyone knows the distance between TV and the jack? It is very convenient and doable with the BO, but there are draw backs to this hitch that trump the benefit of the distance that allows. I am migrating from many years of BO Swaypro into the PP3 after a white knuckles moment that did not end well. Regarding that “situation”, the driver’s side back tire of the F150 read 10 PSI below rating. Wonder if that could have produced or helped a sway that got out of (my) control on a clear day, dry road, no obvious gust, no sudden lane change, change of speed rate, etc.

[ROBERT CROSS]

Originally Posted by BayouBiker

Propride hitches have very very strong damping factors. Nothing can totally prevent sway. I am certain I can demonstrate sway on a combination with a propride hitch. They are marvels, but they can't do miracles.

Very true...if you can break the rear wheels loose on the TV, the AS will 'sway' no matter the hitch.

Bob
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[BayouBiker]

Indeed low pressure and uneven pressure, particularly on the rear of the vehicle will contribute initiation and advancement of sway events.

[Just RVing]

The thing which I experienced was the fact that my weight distribution system wore out after 15 years of use. In trouble shooting the problems, I verified tire pressures on TV and TT, replaced TT tires showing signs of side wall cracking, adjusted the weight bars and then disconnected the TT from TV and found all the stress points were worn out. I had a 100lb equalizer system with 900lbs of tough weight. I upgraded to a 1,400lb tough weight system.

[Collyn]

Originally Posted by ROBERT CROSS

Very true...if you can break the rear wheels loose on the TV, the AS will 'sway' no matter the hitch.

Bob
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Take this very seriously - the AS may not just sway - it is highly likely to trigger a jack-knife.

Collyn

[tjdonahoe]

17 3/4 ton ram 4 X 4 ram 6.7 cumalong. 13 31’ Classic...no sway problems...1000# hitch weight...ram weight at 9000#s. , as has 7800 on the axles..tow unit is heavier than the trailer...Reese duel cam..the tail does not wag the dog here...

[tjdonahoe]

Originally Posted by ROBERT CROSS

When it appeared on the sidewall possibly?

FWIW.... AS even recommended max on the GYM's that were on our AS from new.
We followed that 'recommendation' along with the max speed limit, 13yrs one self inflicted curb rash failure.

Bob
🇺🇸

80#s is the max inflation.

[ROBERT CROSS]

Originally Posted by tjdonahoe

80#s is the max inflation.

Yep...that's why it's on the sidewall and why I use it as such.

Bob
🇺🇸

[RTOS_LLC]

Originally Posted by Collyn

Take this very seriously - the AS may not just sway - it is highly likely to trigger a jack-knife.

Collyn

I implemented sway controller years ago and go through these discussions so much I created the following web page

https://www.realtimeobjects.net/video

that provides links to 13 different videos/pages on almost every aspect of trailer sway that I believe can be understood by "the normal human being".

The prior web pages includes very short introductions and summaries to each topic and includes links to what I consider the best on line videos I could find. It is organized as follows;

- How does trailer tongue weight affect sensitivity to a sway event
- What not to do during a sway event
- What does a weight distribution hitch do and how to adjust it, including determining the proper tongue weight
- What does an electronic sway controller do to reduce sway
- Electronic sway control customer testimonial
- Sway controller installation video

My favorite is the customer testimonial as it provides a real users experience using electronic sway control;

https://www.youtube.com/watch?v=V2eAaYsfgmE

I also like the first one reference on the web page, which shows a sway event/roll over while passing a semi truck in Australia. Ya there are tens of thousands asymmetric sway controllers installed in Australia and far far fewer in the USA, believe it or not.

The sequence of videos provided covers each sway related topic, including a "LONG" video (28 minutes) on a test track using every combination of activating and deactivating the "trailer sway controller" and "truck sway controller" and the results of each test. Even includes one test with near zero tongue weight to make a point. This is for those whom want to view reality versus "on paper" discussions.

I recently added an installation video for the DIY trailer owners, created by a sway controller test driver.

I am trying hard to have the web page stick to "just the facts", but more importantly want to point to solutions for those whom have had "white knuckles" in the wind or during an evasive maneuver and want to stop sway via proper loading, proper hitch adjustment and most importantly using asymmetric electronic sway control.

I am more than happy to change/add links if someone knows of better videos out there. I hope the web page helps and appreciate any comments you may have.

[Collyn]

As living in Australia I can confirm there are tens of thousands asymmetric sway controllers installed in Australia.

The very first was invented in Australia (in 1950) but then used far in the USA. They are now they are used here by most owners of travel trailers over about 18 ft.

(We use the term 'caravan' - not 'travel trailer').

Collyn

[1957Custom22]

I’ve been watching YouTube sway-crash dash-cam video clips — over a dozen so far. Elapsed time between onset and jackknife ranged between 3 and 12 seconds, most around 8 seconds. Each side to side swing took about half a second.

Those dash-cam videos make me doubt whether most competent drivers can successfully regain control after the first 3 or 4 side-to-side swings, assuming lack of electronic anti-sway technology such as asymmetric brake controllers or equivalent.

I’m not familiar with any engineering studies on the subject of how to reliably regain control (without electronic assist) after a trailer has seriously started swinging side to side. I’ve read many opinions, none based on successful personal experience or controlled studies.

I agree with those who focus on sway prevention rather than sway recovery. Although I’m well-aware that Airstreams and freight trains have almost nothing in common, we might learn from a study performed decades ago by the Santa Fe railroad.

In 1974, after a series of 12 unexplained freight train derailments at speeds averaging 66 mph, the railroad assembled a special test train with underfloor video cameras and instrumentation. You can see excerpts from the resulting videos on YouTube by copying and pasting the search terms — Workin on the Santa Fe — on YouTube, and skipping ahead to minute 31:45.

With strong winds blowing sand across the track, the wheel-sets of empty freight railcars began swinging side to side at 55 mph on smooth welded rail. The railcar swing cycles were much quicker and narrower than trailer swing cycles, perhaps because flanged wheels and rails prevented wider swings, forcing quicker ones.

The study concluded that the mysterious derailments resulted from flanged wheels climbing over rails during high-speed swing cycles. In those days, freight railcars lacked sway-damping devices, so the railroad’s interim preventative was to reduce some train speeds. Since 2002, all new U.S. freight railcars have included sway-damping devices.

Kits are available to retrofit sway-damping to older freight railcars. One supplier has posted a short animated video on YouTube showing how they work. They depend on the same basic frictional sway-damping principle as many trailer sway-damping devices. You can copy and paste the search terms — Freight Railcar Truck Hunting Constant Contact Side Bearings — on YouTube to see that video.

You don’t need to remind me that mechanical causes of trailer sway are vastly different from those in railroading. Yet in both, dangerous swing cycles can start spontaneously, and once started, they perpetuate themselves until speed is reduced, or there’s a crash. Also in both, the basic preventatives include sway-damping devices plus keeping below critical speeds.

Keeping below your critical speed may be easier said than done. I don’t know of a verifiably-reliable formula or app to calculate your critical speed based on your individual inputs. Most sway-control devices seem to raise your critical speed, regardless what it really may be. I’ll let others debate whether any sway-control device eliminates all sway risk at any speed.

[ROBERT CROSS]

All the evaluationing makes one wonder..."How did I ever make it 34yrs without killing us or others?"🤔
"Too smart to worry and too dumb to care." I guess.
Common sense rules.

Bob
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