Brake Controller Ability to Mitigate Sway

[dkottum]

It's great to learn to use your brake controller even when you are towing with a Hensley/ProPride hitch. You'll be spending a lot of time at the ready to use the brake controller to mitigate sway though. There has never been a sway caused accident in the 25 years the design has been on the market.

[franklyfrank]

Originally Posted by dkottum

Hard to imagine almost 25 years after the first projected pivot point hitch went on the market to eliminate the possibility of trailer sway we are discussing reaching for the brake controller before the whole rig goes out of control. I know, I know, they are expensive. But relative to the $100k+ cost of these truck/trailer combinations and the consequences of out of control sway?

Okay, so much for alternatives. Back to the discussion on using the brake controller to prevent a loss of control accident.

You never miss an opportunity to give PP and Hensley a plug do you ? Are you on commission or something?
As to the above post, I have been using a Blue Ox hitch. Two weeks ago I traveled a full day on I-80 going west with 25 to 30 mph sustained cross winds. It made the rig crab ( or as they say in truck driver lingo dog tracking) but I never experienced any sway. Even when passed by an occasional semi. I did sense the trailer aligning itself straight passing through underpasses but that is not sway. With some experimentation I realized that the best speed for the conditions was 66 MPH. Normaly I would have set the cruise at 72.
In three years of using a Blue Ox in all kinds of terrain and weather conditions (accept snow, and ice) I never had any sway issues whatsoever with the Blue Ox. It is an awesome hitch that keeps you safe, doesn't brake the bank and doesn't come with 23 pages of installation instructions. It took me less than an hour to install, and I can hook up an ready to roll in less than 15 minutes.
As to the brake controller, as it has been mentioned countless time, especially the factory installed units, simply increase the gain going down hill. I normally have it set at 6 and for down hill decent or wet road conditions I set it 8. I have been using this procedure on 30' AS the last 5 years and it work great for me.

[franklyfrank]

Originally Posted by uncle_bob

Hi

To be effective in terms of anti-sway, the brake controller needs to be able to *detect* sway. That's not as easy as it might seem.

Bob

There are electronic Sway Control systems available that do just that. Detect sway and apply the trailer brake accordingly.
Even Dexter offers one for their axles. I have recently contemplated to install one for added insurance but since I haven't had any sway issues with my Blue Ox hitch I decided against it.

[guskmg]

Not previously mentioned is the inherent return to center forces designed into all WD hitches. They tend to return to center and therefore do provide some sway prevention, but it is not enough when things suddenly go South. The same applies to friction sway controls. However, these devices do not work when roads are slippery, and there use is not recommended under such conditions. So when friction sway control is most needed it is not usable. That is why trapezoid hitches like Hensley and ProPride are so effective. The cost/benefit ratio still favors them.
guskmg

[franklyfrank]

Originally Posted by RandyNH

In this video, which I'm sure most have seen, I do not believe compression or excessive momentum are factors. VIDEO



Are you under the impression that people using engine/exhaust braking are in 4WD? It would surprise me, if anyone was in anything other than 2WD, except in extreme situations



Weight distribution doesn't really play a factor in sway control. As in the video above, tongue weight does, but WD is moreso just about the numbers and trying to get everything level. I've never read anywhere where WD helps sway. (If anyone has, please let me know, I do enjoy digging and doing research)

As an added explanation.. when reviewing most of the YouTube videos you can find, from dash cam points of view, most vehicles are in the process of passing a tractor trailer truck, no compression and it would seem a light enough tongue imbalance that the bow wave upon impacting the nose of the trailer causes the sway to begin. AUSSIE VIDEO

IMHO the sway begins with changing lanes to set up for the pass and attempting to get back to the right lane too abruptly. Non of the videos show the set up part. I believe that trailer begins swaying for whatever reason before the so called bow wave. Which I have yet to experience while I am passing a semi. Since you are traveling at a greater rate of speed I believe just the opposite happens. You create a bow wave while passing a vehicle that effects them.
Since all commonly used WD hitches provide very good and reliable sway control and prevention we can also assume that these incidents were due to either using badly set up a sway control hitch or one that doesn't have any.
Or perhaps someone self installing a ProPride and miss reading 13 pages of the 23 pages of instructions. We will never know.

[slowmover]

Stopping sway is simple: Floor the accelerator while simultaneously jamming the trailer brakes.

One doesn't have long seconds. Might have one or two.

Hitch tension is needed NOW. The trailer needs to return to center NOW.

Full engine power is needed NOW to counteract the trailer weight.

The NEED to accelerate means constant vigil over vehicle spacing. Especially on a downgrade.

And despite above comment, a VPP hitch goes into compression on a downgrade. NO conventionally-hitched trailer remains under tension either.

Any slowing of the TV must be countered by TT braking; a TV using an exhaust brake or transmission braking WITHOUT simultaneous TT braking has the hitch in compression.

The brake controller in and of itself does not mitigate TT sway. Electronic anti-sway uses the trailer brakes, but that function is by a device separate from the controller, whether the bargain-brand Prodigy or top shelf DIRECLINK.

.

[slowmover]

Originally Posted by SteveSueMac

For whatever it's worth - I use a ProPride. I wrote about practicing using the brake controller. I'm sure the hitch prevents sway from happening. That doesn't mean I shouldn't be prepared with belt and suspenders. What possible harm could there be in using a PP and having the muscle memory to deal with an unexpected incident? What if a component failed on my hitch? What if I'm on a 9% grade downhill using my diesel exhaust and that collapses the linkage? There is just no reason not to be prepared for anything...

Belt and suspenders would be a VPP hitch with the add-on TUSON electronic anti-sway (also sold under other names, such as DEXTER). It will react faster than the vehicle operator.

But reliance on that device is with the understanding that the trailer tail may be into an adjacent lane prior to or simultaneous with activation.

And the lower the TT tire pressure from the recommended full inflation, the sloppier the TT response to correction. Bad slip angle mojo.

.

[overlander63]

Originally Posted by slowmover

Stopping sway is simple: Floor the accelerator while simultaneously jamming the trailer brakes.


.

That's great. Except when you floor the accelerator, and the truck returns to idle, instead of accelerating. Now what do you do?

[slowmover]

The engine doesn't return to idle until one let's off. You won't be letting off, not at highway speeds. Too much momentum in that trailer as it's swinging thru its arc.

One won't be releasing the throttle OR the TT brake for a fair distance (related to initial speed, etc) as horsing that trailer into alignment AND keeping it there continues through making an emergency stop on the shoulder to inspect the rig.

If one were taught the stupid "rule" of right foot braking, now is the time to change. (It's more exciting with a clutch, 'cause then one wants to know heel & toe method for simultaneous throttle and brake feathering. And how to downshift in such an event to keep the engine from stalling).

Keep your foot OFF the service brake.

Given no mechanical failure, the point at which to use the service brake is a ways down the road.

And hit the four ways as soon as you remember it.

But there's not a split second to lose initially.

.

[uncle_bob]

Originally Posted by pteck

False. Sway situations are setup well before sway actually occurs.

.

Hi

Ok, if you can design a purely brake based anti-sway system that takes care of sway with no feedback, there's big money in it. Every brake based system I've ever seen needs feedback.

Bob

[pteck]

Originally Posted by uncle_bob

Hi

Ok, if you can design a purely brake based anti-sway system that takes care of sway with no feedback, there's big money in it. Every brake based system I've ever seen needs feedback.

Bob

I believe we're talking past each other.

What I'm talking about is inherent stability under braking. Rather than active stability correction under braking.

An analogy would be on a solo vehicle, brake bias vs. ABS. Under the limit braking vs. over the limit braking.

The former maintains composure and stability when bias is correct, to mitigate sway. The latter actively corrects sway once it has set in.