Trailer Tire Pressures?

I still haven't found anyone needing anything moved from the Fort Worth area to Hollywood Ca. so I will have to be towing the trailer empty one way. For those that haven't read the other thread this trailer has dual axles and every so often one of the wheels takes a bounce and locks up and off the pavement which changes the towing dynamics. Which is just another way of saying you get and "Oh E36 M3" moment.

One way I want to help minimize this is to lower the tire pressures when the trailer is empty. That should soak up some of the bounce. But what's a good pressure?

From my Dune Buggy, Locost, and other light car days it appears that at that weight I should/could run as low as about 14 psi. but will that cause enough tire squirm that it could cause a blow out on the trailer tires? These are real trailer tires and not car tires.

Would it help to put a few hundred pounds of disposable ballast on there? Sandbags, etc? Might settle things down a bit. I always hated pulling an empty trailer.

My favorite disposable ballast has always looked like Merkur XR4Tis

Sounds like you need to back off the trailer brakes a bit.

I had an open trailer that would bounce when unloaded, but other than making noise it was never an issue. Underbraking it could hit a bump and lock a wheel while in the air, but backing off the brake controller helps. You don't need much trailer braking on an unloaded open trailer.

This isn't a braking event. It happens at bumps. I will be buying some gardening soil to tote around. I did that last time, but it's a pain to keep moving around and to place once we load the trailer up.

With the dual axle there is a little triangle thingy in the middle of the suspension that both sets of springs attach to. This can pivot and it will allow an axle to stick in the up position. It's not a big deal if the front axle sticks up since that leaves the trailer nose heavy but things get interesting real quick when the rear axle disappears and the trailer becomes nose light.

You can't find a free something and dispose of it in Hollywood?

"Hey mudsliders, I got some sandbags for ya" Put the weight right over the axle.

Dan

Someone thought of an old waterbed, but I haven't been able to find one. But back to my basic question, tire pressures.

Is there something inherently different about a made for a trailer tire that wouldn't let me run a very low tire pressure?

Would it build up heat and cause a blow out?

It's a 1400+ mile trip

I would say that they would heat up, but don't know for sure.

How about two 55 gal drum full of water. Drums can usually be found for cheap. Around here they can be had for $15-$20. Full would be over 800#, empty next to nothing. Also easy to strap down.

Sounds as if the shackles go over center. Some sort of bump stop might help.

Most "real" trailer tires run in the 55 to 85 psi range. My single axle open dwarf trailer uses 14.5 moblie home axle and tires there suposed to run @ 85psi but as there are no springs at all its wicked at that presure i run about 45psi and the tire seem to wear quite a bit better too.

Use your pyrometer to tune the presure on your way out. aim for a temp spread of 5 deg.

I check my tire temps any time i stop with my 20ft enclosed twin axle unit just to be on the safe side.

44

John Brown wrote: My favorite disposable ballast has always looked like Merkur XR4Tis

For me it's the mother-in-law.

carguy123 wrote: With the dual axle there is a little triangle thingy in the middle of the suspension that both sets of springs attach to. This can pivot and it will allow an axle to stick in the up position.

Something is wrong then. I have never seen that happen ever. Fix the trailer.

Let me put some tire pressures into perspective for you. I have an old motorcycle utility trailer. One of those that you tow behind the motorcycle. Empty, it weights 40 lbs. Fully loaded, it's usually about 200 lbs. I have standard little trailer tires on it.

When the trailer is empty, the tires are empty. As in zero psi. No problems with heat or squirm. The trailer tracks nice and level and calmly up to nearly 100 mph. At about 100 mph it does sometimes start to dance back and forth.

When the trailer is loaded with it's tiny weight, I sometimes run upwards of 5 psi or so. Again, no problems with heat, no squirming, etc, until about 100 mph.

I have tried actual tire pressure in them. Like 20 psi. The trailer is completely uncontrollable then. It bounces everywhere and is hardly ever on the ground.

So no, I'd have no fear of dropping the tire pressure way down on a completely empty trailer. I'd drop it down until the trailer behaved and just watch for excessive heat. Balance the two and go!

joepaluch wrote:

carguy123 wrote: With the dual axle there is a little triangle thingy in the middle of the suspension that both sets of springs attach to. This can pivot and it will allow an axle to stick in the up position.

Something is wrong then. I have never seen that happen ever. Fix the trailer.

I've talked to the manufacturer and they they say just tighten the bolts which I have done. It looks as if that point ought to be fixed rather than pivot. Or if it's going to pivot it needs to be loose enough to pivot all the time. I'm afraid that by tightening the bolts I have made the problem worse. If I have probs on the trip I'm going to loosen the bolt.

Since no one has any thoughts on lower tire pressures I'm going to do that to put some give in the suspension and I'm thinking that will help solve the issue. Added my pyrometer to the pile of tools to take with me.

carguy123 wrote: Since no one has any thoughts on lower tire pressures I'm going to do that to put some give in the suspension and I'm thinking that will help solve the issue. Added my pyrometer to the pile of tools to take with me.

Try reading my post. Tire pressure is all I discussed.

foxtrapper wrote: When the trailer is empty, the tires are empty. As in zero psi. No problems with heat or squirm. The trailer tracks nice and level and calmly up to nearly 100 mph. At about 100 mph it does sometimes start to dance back and forth. When the trailer is loaded with it's tiny weight, I sometimes run upwards of 5 psi or so. Again, no problems with heat, no squirming, etc, until about 100 mph.

Is there a reason you are driving with a trailer of any size at 100 mph???

SVreX wrote:

foxtrapper wrote: When the trailer is empty, the tires are empty. As in zero psi. No problems with heat or squirm. The trailer tracks nice and level and calmly up to nearly 100 mph. At about 100 mph it does sometimes start to dance back and forth. When the trailer is loaded with it's tiny weight, I sometimes run upwards of 5 psi or so. Again, no problems with heat, no squirming, etc, until about 100 mph.

Is there a reason you are driving with a trailer of any size at 100 mph???

Cruise control set at 85, need to punch it to get out of a hairy situation.

SVreX wrote: Is there a reason you are driving with a trailer of any size at 100 mph???

Because if I went faster, it got squirrely. Otherwise, I'd be telling you what it towed like at 140 mph.

Usually when I'm towing a tandem axle trailer empty over long distances I chain the front axle up and let it run on just the rear wheels. Takes about 10 minutes to set up on both ends and lets it pull easier and get better fuel economy. One trailer I even built with tabs on it so I could "hang" the front axle with just a pin on each side.

oldopelguy wrote: Usually when I'm towing a tandem axle trailer empty over long distances I chain the front axle up and let it run on just the rear wheels. Takes about 10 minutes to set up on both ends and lets it pull easier and get better fuel economy. One trailer I even built with tabs on it so I could "hang" the front axle with just a pin on each side.

I looked at doing that, but I can't find a way to attach it to. But I'm going to look again.

I've got the front tires off now so I have to revisit the suspension after the snow visits us tomorrow but I'm afraid that will beat the suspension to death with the wheels off.