Trailer Sway Control

[RUSSELL5000]

Please note that I don't want this thread to turn into another heated argument on this topic.

I have seen a number of advertisements regarding devices that detect trailer sway and apply the trailer brakes to eliminate trailer sway. Hayes advertises a product ("Sway-Master" electronic sway control); Jayco advertises such on their travel trailers ("Sway Command" tow control technology).

The Hayes product says "SwayMaster® is designed to eliminate trailer sway through the use of solid state gyroscope and GPS technology. While the solid state gyroscope and GPS are always active and monitoring sway, at 45 mph the unit initiates a speed sensitive quick reaction braking boost when sway is detected to recover stability or to counter instability."

So, a simple question: does anyone have any experience with these new products?

Thanks much!

 

[Cummins12V98]

IMHO use PLENTY of truck to tow a TT! Sorry that is the real fix.

 

[Hoefler]

IMHO use PLENTY of truck to tow a TT! Sorry that is the real fix.

AND proper loading!

 

[Grizzly]

The tow truck should always weight more than the trailer. Shocks on the trailer will also help.

 

[SnoKing]

The tow truck should always weight more than the trailer. Shocks on the trailer will also help.

That would limit the size for 5th wheel trailer greatly! Oh! This is about bumper pulls. They are down right hard to control if not loaded correctly! SNOKING

 

[RUSSELL5000]

I have looked at lots of youtube videos of bumper pull trailer sway. Common observations:

Higher speeds

Lighter trucks

Windy (from comments)

Not universal, but commonly observed. Loading is harder to tell in a video.

Certainly agree that having enough truck and proper attention to set-up and loading are essential prerequisites.

But to return to the question: anybody had any experience with these devices? Do the statements make sense?

Thanx!

 

[Grizzly]

That would limit the size for 5th wheel trailer greatly! Oh! This is about bumper pulls. They are down right hard to control if not loaded correctly! SNOKING

Maybe not. If you transfer the pin weight of the 5th wheel to the weight of the truck, say 2000 lbs, the trailer would weigh 2000 lbs less and the truck would weigh 2000 more. Yes a 5th wheel is very different than a TT because the pin weight is just forward of the truck axel.

 

[GAmes]

The tow truck should always weight more than the trailer. Shocks on the trailer will also help.

That seldom happens. A million 18 wheelers disprove your theory every day. Probably just as many pickups with trailers as well.

 

[GAmes]

But to return to the question: anybody had any experience with these devices? Do the statements make sense?

As you know, I have no experience with sway, thus no experience with an electronic sway control. However, I think the concept would be a lot more effective than some gizmo attached to the bumper. My question is does the device alert the driver that it is actuating the trailer brakes? If the trailer has a defect sufficient for it to be swaying a person could be burning up a lot of brake shoes.

 

[B.G. Smith]

I never had any problems with the old friction device that connected to the a-frame of the trailer and the equalizer hitch. Just make sure the tires on the tow vehicle and the trailer are inflated to the maximum allowed by the tire manufacturer. That thing sounds way too complicated for me. bg

 

[RUSSELL5000]

GAmes,

I have never actually seen one - just read about. The websites say that the speed is derived from GPS readings and that the gyroscope provides parameters on sway.

The system is inactive at lower speeds. The idea is that the system will not activate hen making a significant turn, and significant turns occur only at lower speeds. Looks like the system is inactive until 40/45 mph.

If the trailer is going fast enough and sways then the trailer brakes are applied enough to slow the trailer so that it gets pulled back into a straight track.

I can't tell whether the driver is alerted or not. Yes, some type of defect causing sway would be a concern. I don't know how it would react, although I assume by activating the brakes, same as your assumption.

Other questions not addressed directly:

Will it work equally well with disc brakes versus drum brakes?

What happens if the GPS signal is lost?

What happens if there is a brake failure?

Jayco states that it will be standard equipment on the bumper-pull trailers. You would think someone would have looked into carefully since they did that.

 

[Grizzly]

That seldom happens. A million 18 wheelers disprove your theory every day. Probably just as many pickups with trailers as well.

As SNOKING said on post #5, this is about TT. An 18 wheeler is vastly different from a TT.

 

[AH64ID]

Maybe not. If you transfer the pin weight of the 5th wheel to the weight of the truck, say 2000 lbs, the trailer would weigh 2000 lbs less and the truck would weigh 2000 more. Yes a 5th wheel is very different than a TT because the pin weight is just forward of the truck axel.

This again!?!

There is no weight transfer. There is weight carried by the TV but isn't transferred. Wether it's 1200lbs of TW or 2000lbs pin weight it's still trailer weight. Wait, weight doesn't matter as the vehicle transfers all its weight to the road! Everything is free of weight!

Not all 5th wheel hitches place the weight forward of the axle.

 

[Cummins12V98]

"Not all 5th wheel hitches place the weight forward of the axle."

I have my hitch 2" forward C/L of rear axle. 5,500# pin and less than 150# transfers to the front axle.

 

[AH64ID]

"Not all 5th wheel hitches place the weight forward of the axle."

I have my hitch 2" forward C/L of rear axle. 5,500# pin and less than 150# transfers to the front axle.

Yeah it's not much, but at least it doesn't decrease the FAW.

 

[Grizzly]

This again!?!

There is no weight transfer. There is weight carried by the TV but isn't transferred. Wether it's 1200lbs of TW or 2000lbs pin weight it's still trailer weight. Wait, weight doesn't matter as the vehicle transfers all its weight to the road! Everything is free of weight!

Not all 5th wheel hitches place the weight forward of the axle.

I respect your opinion, but this time I can't agree. Perhaps 'transfer' wasn't the appropriate word here. If you place weight on the truck, that makes the truck heavier and the trailer lighter.

 

[NIsaacs]

Perhaps 'transfer' wasn't the appropriate word here. If you place weight on the truck, that makes the truck heavier and the trailer lighter.

Transfer makes sense to me. If you take an empty 10k truck and attach it to a 12k trailer that has a 2k pin weight, that truck is now 12k and the trailer becomes 10k. Trailer gvw's are starting to add axle gawr plus pin weight to arrive at the trailer gvw. For example, I have 14' equipment trailer with (2) 3500lb axles, that's 7k, yet the trailer gvw is 8750. They assume you will "transfer" the excess (1750) to the truck hitch.

Nick

 

[GAmes]

As SNOKING said on post #5, this is about TT. An 18 wheeler is vastly different from a TT.

You missed the point. It isn't the tow vehicle that causes or cures sway, it is the trailer. I could easily improperly load one of those little tow behinds for motorcycles to the point it swayed bad enough to topple the bike. Hook that same trailer to my duelly and it would still sway, but obviously wouldn't affect the truck's handling.

That leads to another question about these electronic devices. What is it's definition of sway? Is it the real definition as depicted by the out of control oscillations shown on u-tube or the little wiggle from passing trucks? If it is the former, it is just an amplification of the scam carried on in the RV market and if it is the latter I would have worn out a set of brake shoes during my last trip across NE and WY.

 

[SnoKing]

Transfer makes sense to me. If you take an empty 10k truck and attach it to a 12k trailer that has a 2k pin weight, that truck is now 12k and the trailer becomes 10k. Trailer gvw's are starting to add axle gawr plus pin weight to arrive at the trailer gvw. For example, I have 14' equipment trailer with (2) 3500lb axles, that's 7k, yet the trailer gvw is 8750. They assume you will "transfer" the excess (1750) to the truck hitch.

Nick

The trailer weight is what it is. The hitch weight can be on the jack or the back of the truck, but the weight is just that. In fact with 5th wheels there is more weight of the trailer tires when attached to a truck than when setting on its landing gear due to the placement of that landing gear, not so much on a bumper pull.

Bumper pull stability is a combination of many factors, including a tow vehicle like a dually that will not get pushed around as much as a SRW truck will.

Years ago they use to tell you to hit the trailer brake manual lever to pull a trailer out of a sway condition, until they found that is did not really work! So if this device can control the left and right brake individually, then it might work. That is trailer is going "right" apply "left" brake and the other way around.

You are how ever introducing a black box into the brake system that if fails could effect braking in general, so it seems there is a fair amount of product liability involved. SNOKING

 

[NIsaacs]

The trailer weight is what it is. The hitch weight can be on the jack or the back of the truck, but the weight is just that. SNOKING

If that's the case, how do you get GCW?

Nick