Trailer bounce

[SmokeyBob]

Has any one lowered their tire pressure to keep the trailer from bouncing.

[Gage]

I put shocks on my tear. Now no bonce. Suspension works just like a car. But I also have a 1500# teardrop.

[DezPrado]

I tried it on mine seeing as how the trailer was so light even fully loaded for the recommended 4x4 tires on it. They match the TV. Lowering the pressure substantially softened the ride enough, but the trade-off is increased tire wear I expect. So far so good though. Considered shocks at one time but the rubber torsion type suspension hardly lends itself to a simple solution in my case

[48Rob]

Bob,

Yes, often.

Many people "believe" that the correct tire pressure for a tire is that which is listed on the tire.
The pressure listed on the tire is the maximum pressure "that" tire can handle.
Tires are made to fit a wide range of vehicles. Manufactured vehicles generally list the tire size and pressure appropriate for that vehicle. For a home built, it is up to the owner to determine the correct pressure.
The chalk method is most common and easy to use to determine the correct pressure for a given load (your trailer, loaded to go camping).
Draw a heavy line across the tread of each tire, then drive around the block (on a dry day of course).
If the pressure is correct, the chalk will be worn off evenly. If you have them over inflated, the chalk will be worn off in the middle, but not the sides.

If you get the tire pressure right, but the trailer still bounces, then the springs were not engineered (calculated to fit the load) correctly.
Most utility trailers that home builders use as the base for their trailers are designed to carry a given weight. Loaded at or near that weight, the trailer will ride reasonably.
If the trailer is designed to carry 3000 pounds, but your completed camper only weighs 1000 pounds, it will ride like a dump truck.
The dump truck reference, in case some do not understand, is about the way a dump truck is sprung.
They are designed to carry a great weight and thus have very stiff springs. When the dump truck is loaded, it rides very nicely, but when empty, it is a very uncomfortable, bumpy ride. Newer dump trucks now have air ride (air springs) which adjust to the load so the ride is always comfortable.

If you have a rubber torsion axle, your "springs" are not adjustable and a different axle sized to your load may be needed.
If you have leaf springs, most often they can be adjusted to lower the capacity, to closer match your load.

Rob

[Socal Tom]

I tried it on mine seeing as how the trailer was so light even fully loaded for the recommended 4x4 tires on it. They match the TV. Lowering the pressure substantially softened the ride enough, but the trade-off is increased tire wear I expect. So far so good though. Considered shocks at one time but the rubber torsion type suspension hardly lends itself to a simple solution in my case

Actually, over inflated tires can wear out faster as well. The key is spreading the load across the whole tread not just the middle. That's where the chalk method works. Some of the tire mfgs have posted a pressure/load tables on the web. If you search my posts, I've linked to a couple of them.
Tom

[MtnDon]

Chalk: I have found that the floor of my garage / workshop is ideal when it has a thin dusting of sawdust. I just back in whatever I'm checking and see if the entire face of the tire picks up sawdust. You wear out the center of the tread if too highly inflated and wear out the edges if too low.

[Vedette]

I agree with what Rob says!
Most builders (of anything) go with the old "if something will do, than more is better" theory!
From a lot of Teardrop owners I have spoken with about their axles, this theory is used by most.
If you think your finished trailer weight is 1000 lbs and plan to carry 200 lbs of beer, food, clothes and equipment in it bringing it to 1200 lbs........ then most people think to be safe they should have a 1500 lb or 2000 lb axle.
Well if you do that, then you can expect your trailer to ride rough! Especially when empty.
I ordered an 1100 lb #8 axle from Dexter for Miss Piggy when I was building her. Our final loaded weight while travelling is 1450 lbs.
It rides and handles like a dream! Could not be happier! We 165 x 15R tires that show absolutely no wear, after 21,000 miles.
Tongue weight is another factor to consider......you need some!
Some people brag about 50 or 80 lbs of tongue weight. Well expect your trailer to rattle and bounce about with that weight.
150 - 200 lbs of tongue weight will make your towing experience more enjoyable!
I am ordering our axle for Kermit this week ..........and plan on it being the same as the one we have on Miss Piggy.

[S. Heisley]

I copied the information, found below, from somewhere on this forum. (...forgot to copy the source address; so, that is lost.)
I calculated my tire pressure, based on 1500 lbs, which is a little high but works, and printed and taped that PSI to my tire inflator so that I would have it whenever I needed it. (I also taped the PSI of my car tires to the inflator; so, I have both available without having to hunt for it.) Thus far, this advice seems to have served me well.

If I'm reading your question correctly, you want to know if running a certain tire pressure will do something good or bad for the trailer...Absolutely!

The way your finished, loaded trailer rides is directly affected by what tire pressure you're running. Running a very low air pressure will make the trailer more likely to wiggle and sway behind the tow vehicle. It will seem very bouncy and squishy and wear the tires on the outer edges. If a high PSI is used, the trailer will ride very harsh. Hitting bumps will make the trailer want to jump. The tires will also be over inflated and wear in the middle.

For even wear and a pleasant ride, there is an optimum PSI.

If you know the weight of your trailer loaded and ready, you're half way there. Take your trailer for example: GTW 1000. If balanced correctly, the tongue should have a weight of 100# and each tire should share the rest of the load at 450# each.

Lets say your trailer has 4.80-12 tires rated at a max load of 750# at 60psi. If you take your trailer weight knowing that only 450# is going to be riding on each tire, it's just a simple math formula.

Take your load per tire (450#), multiplied by the max PSI of the tire (60), divide that by the max load of the tire (750), and you get what should be your correct PSI for maximum ride and wear quality.

450x60= 27000/750= 36PSI

So, in this case, your trailer will perform best with a tire pressure right around 36PSI.

This formula can be applied for any tire as long as you know the max weight, PSI, and the actual weight it will be carrying.

[Dalorin]

I'm glad that I stumbled onto this thread. This has had me really concerned as well.
I had a custom trailer assembled for me that has full sized 14" tires. Because of the larger tires the manufacturer used a 3500 lb axle. Driving the thing home with no weight at all it bounced like it was going to shake the car apart. I think the leaf springs were matched to the axle. Now I'm worried that the finished camper will shake itself apart when I get done with it.

Is this simply a matter of removing one of the leafs from each spring? Will that be enough? If anyone can point me to some information in this regard I would appreciate it.

Dorian

[48Rob]

Dorian,

Look here;
viewtopic.php?f=35&t=33375

[Dalorin]

Thanks Rob!

That's good information. Those springs look almost identical to what I have on my trailer. Same overall capacity. I figured removing the lower leaf would lower the capacity around 1000#. I'm definitely going to do this.

It's also interesting that I just got this trailer and the leaf springs are already rusting. I may hit them with some wd-40 or grease. I thought rust was just part of having springs.

Great information.

Dorian

[Socal Tom]

Here is the inflation chart for Maxxis trailer tires,
http://www.maxxis.com/trailer/trailer-t ... tion-chart

Here is a link to a thread on suspension tips that I wrote.
viewtopic.php?f=2&t=49677

Another mistake people make is over tightening the bolts on the leaf springs. They need to be able to move to do their job.
Tom

[PaulC]

I agree with what Rob says!
Most builders (of anything) go with the old "if something will do, than more is better" theory!
From a lot of Teardrop owners I have spoken with about their axles, this theory is used by most.
If you think your finished trailer weight is 1000 lbs and plan to carry 200 lbs of beer, food, clothes and equipment in it bringing it to 1200 lbs........ then most people think to be safe they should have a 1500 lb or 2000 lb axle.
Well if you do that, then you can expect your trailer to ride rough! Especially when empty.
I ordered an 1100 lb #8 axle from Dexter for Miss Piggy when I was building her. Our final loaded weight while travelling is 1450 lbs.h
It rides and handles like a dream! Could not be happier! We 165 x 15R tires that show absolutely no wear, after 21,000 miles.
Tongue weight is another factor to consider......you need some!
Some people brag about 50 or 80 lbs of tongue weight. Well expect your trailer to rattle and bounce about with that weight.
150 - 200 lbs of tongue weight will make your towing experience more enjoyable!
I am ordering our axle for Kermit this week ..........and plan on it being the same as the one we have on Miss Piggy.

Brian, to expand on the highlighted area, a good rule of thumb is to use 10% of the total weight for your tongue weight. Roly would have a major problem with the kind of weight you have recommended
Cheers
Paul

[Vedette]

Hi Paul
Yes we camped with Roly a few times last year (he was next to us all three times) his tongue weight is so low, that the first morning he was at the Dam he set his fresh plate of breakfast on his rear counter, and his trailer did a tail stand dumping everything on the ground. So 2 lbs may have been a little extreme. The Stealth actually looked like it was trying to achieve take off when he crossed some of those cattle guards on the detour we took over the Humbolt mountains on the way to the IRG???
But it is easy for our 83 year old friend to maneuver around the campsite!

[SmokeyBob]

Thanks to everyone for your help. I think I'll try the chalk on the tires. I should have posted why I was interested in lower the tire pressure.

Recently Judith acquired a Quantum Q6 Edge power chair. The chair weighs around 275 lbs. Our Chev HHR is too small for the chair to fit inside. I have a class 1 hitch on the car. Max tong weight is 200 lbs. The weight of a carrier plus the chair weight would be over 300 lbs. So my only option was to buy a small utility trailer to transport this chair. I had read in an earlier post, a long time ago, that lowering the tire pressure would help with bouncing. I searched for the post but couldn't find them. So that's why I asked about lowering the tire pressure. I didn't just want to guess at the tire pressure.

This trailer is a Carry-On 3.6 X 5 feet trailer. Load capacity is 1800 lbs. 12 inch tires. Each tire is rated at 990 lbs at 90 psi. I thought I could drop the tire pressure by 20 or 30 lbs but I just don't like guessing at this. I would rather be safe than sorry.

Anyway thanks to everyone for your help. Here's a pic of Judith in her chair.