tire wear

[gregshannon]

decided to repack the bearings this weekend, getting ready for the big trip in a couple of weeks. When I took the wheels off I noticed that the tires seem to be wearing only on the outside. Not being to familiar with the axle system on Bolers, I'm wondering if this is common, is something out of alignment or is the suspension shot.

Any thoughts

[Chuck-H]

If the tire is wearing on both sides and the center is not, then you are most likely underinflated air pressure. If the center of the tire is wearing out, it is over inflated.
What tire pressure are you running COLD vs the max psi on the sidewall of the tire?
chuck h.

[Angelo F.]

Make sure your axle isn't bent. Laying on the ground looking at the axle - if it's bowed upward (towards the bottom of the camper) in the middle (usually from running over a rock or stump,) there's your problem.

[gregshannon]

The tires are only wearing on the outside, so I guess I better check the axle

[Roy in TO]

Angelo F. Posted Today, 12:55 AM
Make sure your axle isn't bent. Laying on the ground looking at the axle - if it's bowed upward (towards the bottom of the camper) in the middle (usually from running over a rock or stump,) there's your problem.

Not in all cases. I've got a leading edge torsion axle. The axle was tucked in behind the cross frame where the floor raises under the dining table/bed. My axle has an upward bend in the exact center which would be almost impossible to get without bending the cross frame at the same time or somehow at least marking it to show damage has occured.

If you check the Henschen Axle Plant Tour, you will see the axles are actually bent for alignment purposes.

The tires are only wearing on the outside, so I guess I better check the axle

It is possible something could be out of alignment, or if the rubber torsion has weakend (very likely), the trailer would be setting lower altering the alignment. So an axle check is in order. Some of the early model trailers had lighter duty axles, which in some cases were too light for the fully loaded trailer. If you check the Scamp history, you will find that the weights keep going up on the trailers and the axle load specs increased over the years.

[Andy H]

I had the same problem.
Had new tires installed and after one trip to Kelowna and back,,,the outsides were about 50% worn while the insides were like new !
I returned to the Tire Shop and was advised that the axle/suspension was shot.I went to a couple of frame/suspension shops and was advised they didn't align these units and considering the age of the rubber torsion suspension,,,replacement was required.
Approx $500.00 later a new axle was installed and that should cure the problem,I say should because we haven't used it since.

[Benny K]

The bent axle appearance is for the camber angle....this forces the tires to be closer together between the bottom of the tires and further apart at the top.....I suppose if the axle was extremely bent it could cause the unusal tire wear.....I think that if the rubber suspension was kaput you would get unusal wear on the inside of the tire because your wheels would be canted in at the top.......now if your toe in was too much, that could possibly cause outside tire wear as the tires would scuff on the outer tread area trying to track in a straight line.. ..Benny

[Brian B-P]

I believe that Roy is referring to a leading arm suspension: these rubber-sprung "torsion" axles (such as Dexter's Torflex) has an arm on each side and usually the unit is mounted so the arms lead back from the frame mounting to the wheels... that's trailing. Some trailers had the same suspension/axle unit mounted turned around, with leading arms so the wheels are ahead of the rest of the suspension.

The reason it matters is that the drag of the tires will tend to pull leading arms apart, putting them at an angle which increases the tendency to pull apart (causing toe-out alignment), so a bent assembly or weak rubber might allow too much toe out. It's just a possibility.

Which way is this Boler?

[gregshannon]

The arms are leading forward, which I thought would encourage the wheels to splay, causing pre-mature wear on the inside.

Could be right, could be wrong. Anyhow, I think it's a problem for the RV shop (in the fall)

[Benny K]

My 74- 13' Boler has leading arms and the axle is original as far as I know and I have no unusual tire wear so doubt if that could be cause, but then you never know....Benny

[gregshannon]

Okay, here's a thought...... I was wire brushing the rims, figuring I would throw some paint on while they were off the trailer and I noticed that there aren't any balancing weights. 100 km/hr for any length of time would cause the wheels and trailer so shake a little. Maybe that motion would be enough to push the trailer around.

[Pete Dumbleton]

Be sure that the tire shop understands that trailer wheels are usually lug-centered or lug-centric and require an adapter on the balancing machine, not just the usual cone in the center...

[Brian B-P]

...The arms are leading forward, which I thought would encourage the wheels to splay, causing pre-mature wear on the inside....

I agree, but if the wheels are positively cambered (tilting out at the top) due to deliberate or accidental arch in the axle's cross-tube, they could be riding on the outer shoulders. The toe-out would accelerate the wear, on whichever edge is loaded most heavily is the camber is great enough.

Static (while not moving) camber can be checked with a level (held vertically against the tire; measure from the edge of the level to the rim at top and bottom); however, it will change while moving due to distortion of the suspension's rubber.

Similarly, toe can be measured by measuring the distance between reference points on each tire when those points are at the front, and when they are at the back (use a level, square, plumb bob, or whatever to drop from the reference point to the ground). Again, it will change with the drag of towing.

[Shawn Englehart]

Just wondering what the tire milage should be average for a set of trailer tires. My utility trailer has 15in tires, I just use old used tires and change them every 5 years due to cracking. I figured I should have to do the same for the Scamp, considering I spent $50/tire on the utility trailer and its $150/tire for the Scamp. I bought a set of 3 Goodyear Marathon(sp) 75/80/13 tires in 2005, pulled the trailer anywhere from 7500km to 10000km and have one with the same complaint here, the right side tire worn on the outside and the left tire worn even. I have never replaced a trailer tire from wear, always age or other (puncture of somesort). I figured I would get 40 to 50k out of a set of rotated tires, not 7k (this is also Kilometers, in miles I am well under 6000 miles if not under 5000 miles total on this set of tires). Both trailers have averaged the same milage except the utility trailer has half of those empty, the tires I have on the utility trailer shows no wear and a year older (3 years compaired to 2 years old for the Scamp tires).

[Brian B-P]

Shawn, what size (width) are the utility trailer tires and what does the trailer weigh? I wouldn't be surprised if the Scamp tires are relatively heavily loaded for their size.

Also, the Scamp likely has a higher centre of mass (center of gravity) than the utility trailer (with load), so it will be harder on the outside edges of the tires when turning.

Even considering the undersized tires, 10,000 km doesn't seem like very much tire life to me.

[Shawn Englehart]

Shawn, what size (width) are the utility trailer tires and what does the trailer weigh? I wouldn't be surprised if the Scamp tires are relatively heavily loaded for their size.

Also, the Scamp likely has a higher centre of mass (center of gravity) than the utility trailer (with load), so it will be harder on the outside edges of the tires when turning.

Even considering the undersized tires, 10,000 km doesn't seem like very much tire life to me.

Typical tire width of your pick up truck, I think I am running 235/75/15 this time around but I would have to look. I find that after five years, at most I get a scalloped effect on my utility trailer, but its home made, first regristered in 71-72 timeframe with a 50 era Ford front end and rims. I expect weird things from my utility trailer, parts of it are older then I am, and I am getting to the age where weird things start to happen

On the scamp, I cannot determine any axle damage, but it is an 85 so it is most likely tired. I have noticed damage to one rim and a hub from the lugs becoming loose at one time. I think I just put 2 and 2 together with the shell damage A wheel fell off this Scamp! It was drug on its right side most likely causing damage to the axle as well! Nuts! The frame looked ok when I had the floors out but I did not lift the shell off, I should have but I did not take the kitchenette floor out as it was not rotten. When I redid the floors, I discovered the lower right corner had been completely replaced from about the corner marker to front center and the front bench had been repaired as well. The top has an exhaust burn that is now visable since the paint repair peeled. Adding it all together, I think I know what happened to this poor little Scamp one day in its life, things you wish you were told when at the time of purchase. I don't know if this helps in the repair now, but thanks for listening as a few things are making more sense after typing them out. I may need a new axle.

edit for spelling and add tire photo