will a WDH reduce trailer bounce??

[Daryl and Wendy]

Our combination of a small 4 door suv & small trailer doesn't need a weight distribution hitch (WDH); but, most everything inside needs to be nailed or glued down or it is on the floor due to trailer bounce and 'flipping' (when the hitch is going the opposite direction (up or down) relative to the trailer bumper).

I know there are light weight WDH available, sized for very small trailers; will these moderate how much the trailer bounces??

[Byron Kinnaman]

I don't think a WDH would do much except put extra wear and tear on the Trill's suspension.
Before I purchased my Scamp I had heard about everything ending on the floor. So, when I got mine I made some measurements then off the dollar store, and other places that had plastic storage or organizing containers. I found some that would just fit in the overhead cupboards. Most of the stuff is in those. I can get out what I want without removing the containers.
In the fridge I bought refrigerator containment bars that are compression bars to keep the stuff away from the door.
I looked at what was where and how to keep it from banging into the doors, then adjusted the latches a bit tighter.
Cushions and stuff on the cushions, not much you can really do about that.

One other thing make sure you're not driving too fast for the trailer. Trailer tires are generally rated for a maximum speed of 65mph. Many states towing speed is 55, not all. I believe BC has a maximum of 50mph.

Trailer tire should be inflated to the maximum shown on the side wall. This will help also.

[Frederick L. Simson]

Originally Posted by Daryl and Wendy

I know there are light weight WDH available, sized for very small trailers; will these moderate how much the trailer bounces??

I use a small WDH for my Honda Odyssey - Fiber Stream combination and the WDH has no effect on the trailer's bounciness. I have leaf spring suspension and I feel only shock absorbers mounted on the trailer will have an effect.

[Ed Harris]

I know I feel much less bounce with the WDH than without but I think the trailer feel it about the same?

The WDH setup makes my ride much better and more confidence inspiring by redisributing the load of the trailer on the vehicle.

The trailer still flails around back there,I can see it!

[Mike Magee]

Add shocks to the trailer if possible. Imagine how much you would bounce around if your tow vehicle had no shocks.

[Doug2000]

For further advise, please post some pics of your car and trailer, your hitch setup and what your trailer weight is and your tongue weight is.

What is the current suspension on your trailer, add shocks, that is the last thing I would suggest.

I had a 3500 lbs 14' high wall tent trailer behind my Tacoma with a WDH and it towed like it wasn't back there.

The bouncyness sounds like your torflex axle is worn and your tongue weight is to light.

[kootenaigirl]

I would second what Doug said. If your trailer has the original axle the rubber is probably worn out causing the bounce.

[Brian B-P]

There's a big difference between the trailer bouncing (up and down) and a trailer pitching (nose and tail in opposite directions - tail of tug must go up and down).

A WD hitch would presumably make little if any difference to bouncing, but would affect pitching (at least changing its frequency). I would certainly make sure that the suspension is good before considering adding hitch hardware.

[Jared J]

Originally Posted by Byron Kinnaman

One other thing make sure you're not driving too fast for the trailer. Trailer tires are generally rated for a maximum speed of 65mph. Many states towing speed is 55, not all. I believe BC has a maximum of 50mph.

Trailer tire should be inflated to the maximum shown on the side wall. This will help also.

First, most trailer tires are LOAD rated at 65, not SPEED rated. Contact the manufacturers, that's how I found this out, as I voiced my concern.

Second, if a trailer is much lighter than the tire rating, max pressure could actually cause bounce. I run mine at the 80 psi max, but I have my reasons, and I'm don't have bounce issues.

Third, although I would consider it a bandaid, I can't see how a wd hitch wouldn't help. At least in part, the whole tv would have to do the same.

[gmw photos]

Originally Posted by Jared J

First, most trailer tires are LOAD rated at 65, not SPEED rated. Contact the manufacturers, that's how I found this out, as I voiced my concern.

Second, if a trailer is much lighter than the tire rating, max pressure could actually cause bounce. I run mine at the 80 psi max, but I have my reasons, and I'm don't have bounce issues.

Third, although I would consider it a bandaid, I can't see how a wd hitch wouldn't help. At least in part, the whole tv would have to do the same.

Good Year states in their load and inflation charts on their website that the Marathon tire is speed rated for 65 mph. Some ST tires are actually rated lower than that. The ST tires that came on my camper were speed rated to 62 mph ( 100kp/h, load range J ) according to the tire manufacturer.

I think a Marathon is technically speed rated as an L, because Good Year approves running their LR D at 75 mph ( 120kp/h ) but stipulates you must over inflate them 10 psi ( to 75 psi ) to do so. But they also warn that doing so does not increase the load capacity, and also you must observe the pressure and load limit of the wheel. Most wheels in those typical sizes are pressure approved to only 65 psi, so I would assume that is why GY states the tire only being rated to 65 mph, and 65 psi.

To the original poster's issue of bounce, the first thing I would do is make sure everything is "right" before trying to solve a problem by adding yet another variable, such as a WD hitch. As others have suggested, I would start by evaluating the trailer suspension, verify correct tongue weight, and ensure the tow vehicle suspension is up to snuff as well.

[Daryl and Wendy]

1st - Thank you for your input. It sounds like a WDH will be some improvement, but wouldn't completely smooth out the trailer ride.

I should have noted that the trailer is an early 70s 1300 Trillium.

I keep the tow speed to what is reasonable for the driving and road conditions.
The tire pressure is 28 psi, as stated by Trillium for the 1300.
It tows really straight at any reasonable speed. But seems really harsh over dips and bumps (at reasonable speed).

How do I confirm if the rubber torsion suspension is still viable, or needs to be replaced?

[Thomas G.]

Originally Posted by Daryl and Wendy

..........
How do I confirm if the rubber torsion suspension is still viable, or needs to be replaced?

One way is to have someone look at the control arm (the wheel is bolted to it) while someone else jumps up and down inside the trailer. If most of the movement is in the tire sidewall, the suspension is shot.

[Brian B-P]

I don't know why we're discussing high-speed use of trailer tires, but just to correct a misunderstanding...

Originally Posted by gmw photos

I think a Marathon is technically speed rated as an L, because Good Year approves running their LR D at 75 mph ( 120kp/h ) but stipulates you must over inflate them 10 psi ( to 75 psi ) to do so. But they also warn that doing so does not increase the load capacity, and also you must observe the pressure and load limit of the wheel. Most wheels in those typical sizes are pressure approved to only 65 psi, so I would assume that is why GY states the tire only being rated to 65 mph, and 65 psi.

We got into a deep discussion of this idea in http://www.fiberglassrv.com/forums/f...res-55515.html. I don't see any point in rehashing that here - those interested can read the earlier topic (which is a sticky), especially from about post #37 to post #50. For a summary, Jared sent a query to Maxxis and received this in the reply:

Originally Posted by Jared J

According to the Tire and Rim Association the inflation pressures and load specifications in general for any ST Radial trailer tires, regardless of the manufacturer, are designed and rated at 65 MPH. However, if the speed is higher than 65 MPH, the pressure and load need to be adjusted according to the following guidelines:

From 66 to 75 MPH - the tire inflation pressure needs to increase 10 PSI (not to exceed the maximum PSI the tire is rated for) but requires no load adjustment.
From 76 to 85 MPH - the tire inflation pressure needs to increase 10 PSI (not to exceed the maximum PSI the tire is rated for) and load should be reduced by 10%.

For instance, if your ST tires are Load Range D and have a maximum inflation pressure of 65 psi...

You can go 75 mph with 65 psi, but only with the load which would be allowed at 65 mph and 55 psi.
You can go 85 mph with 65 psi, but only with 10% less load than would be allowed at 65 mph and 55 psi.

[Brian B-P]

Originally Posted by Daryl and Wendy

It sounds like a WDH will be some improvement, but wouldn't completely smooth out the trailer ride.

I think closer to the consensus would be that a WDH could provide some improvement in pitching, but wouldn't likely contribute to smoothing out bouncing to any significant extent, if at all.

When the trailer is bouncing, it is the suspension which is moving (or not moving enough and so the tire sidewalls are handling all the motion) - fixes for bouncing will consist of suspension changes, and possibly tire changes.

When the trailer is pitching, either the trailer suspension or the tug suspension - or both - must be moving at least a bit, so any suspension change could potentially help... but the other part which is experiencing motion is the hitch: the coupler is pivoting on the ball, and any WD system is stretching with the trailer-nose-down motion and relaxing with the trailer-nose-down motion. That changes the natural frequency of the motion, and likely decreases it.

Originally Posted by Daryl and Wendy

I should have noted that the trailer is an early 70s 1300 Trillium.

While a generally sound design, original Trillium frames tended to be weak at the bends where the frame rails become the A-frame of the tongue. Any WD system puts a lot of stress on this area, due to the high force applied by the WD components (typically a few hundred pounds down on the tongue in conventional designs, and several hundred pounds forward on the tongue-mounted brackets with the new Andersen No-Sway design). Before considering any use of WD with an original Trillium, it seems prudent to ensure that that any required upgrades of the frame were done (there was a recall for some years of Trillium), and that the frame is really sound. This is another reason not to prematurely jump to WD use.

Originally Posted by Daryl and Wendy

It tows really straight at any reasonable speed. But seems really harsh over dips and bumps (at reasonable speed).

This sounds like a description of a trailer with a suspension which is not moving properly to absorb bumps, because the rubber used for springs has gone hard.

Originally Posted by Daryl and Wendy

How do I confirm if the rubber torsion suspension is still viable, or needs to be replaced?

A recent topic (http://www.fiberglassrv.com/forums/f...ase-59244.html) regarding Franck's problems with his trailer's behaviour over bumps explored this subject, including links to other topics which directly address suspension evaluation. It's a long topic... I suggest post #97 and #98 for those wanting to jump right to the answer.