Another Tire Question

[Jon Vermilye]

Well, I've managed to wear out a set of tires on my single axel Escape 17B (33,000 miles, so I guess I can't complain). Anyway, the original tires are ST 205/75/15 Goodyear Marathons, "C" range. My rims are rated at 50 PSI, my trailer's maximum loaded weight is around 3025 lbs, with a maximum axle weight of 2820 lbs with the WDH.

I'd like to replace the tires with Maxxis 8008 ST tires since the wear on the Goodyear tires was a bit strange. The tires are almost bald on one side with plenty of tread 180° from the worn side (not edge to edge, but around the perimeter). The Maxxis tires are available as either "C" or "D" rated.

And finally, the question - Since my rims limit me to 50 PSI, and my axle weight is well under the tire pressure for the rims, is there any advantage to going to a "D" rated tire since I can't inflate more than 50 PSI?

[Francesca Knowles]

Originally Posted by Jon Vermilye

I'd like to replace the tires with Maxxis 8008 ST tires since the wear on the Goodyear tires was a bit strange. The tires are almost bald on one side with plenty of tread 180° from the worn side (not edge to edge, but around the perimeter).

Maxxis are great tires, but:

The wear pattern you describe above sounds more like a sign of either an alignment/balance or axle problem than it does an indicator of tire quality. You might want to ask the opinion of a professional tire outfit in case it's a condition that needs correction.

Here's a chart about tire wear:



Good luck!

Francesca

[Jon Vermilye]

The wear pattern doesn't fit any of those examples, or any others I've been able to find - I've asked but all I get is shrugs.

[Francesca Knowles]

Can you post a picture of the tires?

I will say, however, that I think you've gotten an extraordinarily long life from your ST's- from what I've been told, even 20,000 miles is considered a good return in that department!



Francesca

[David Tilston]

If I had to guess you are suffering from a very badly balanced tire, but I am no expert, and that is just a shot in the dark.

[Jon Vermilye]

Could be, but they were balanced at Escape, and I would have expected to be able to feel the tire hopping if it was that bad, although maybe not...

As to photos, I can probably do that after Sunday - they are under snow, but we are expecting a 50° day by then so maybe I can get to them.

[honda03842]

I had odd tire wear on the driver's side tire. The inside of the tire was worn almost to the belts in a spot but it was only noticeably worn on about 180 degrees of the tire.

The bearings had been repacked just before we bought the trailer. It appears that the nut holding the bearings in was not properly tightened allowing the wheel to wobble.

I discovered what I think was the problem by jacking one side of the trailer up and could move the edges of that tire in and out. I replaced the tire, repacked the bearing and no more in/out motion at the edges of the tire.

[Carol H]

Originally Posted by Francesca Knowles

I will say, however, that I think you've gotten an extraordinarily long life from your ST's- from what I've been told, even 20,000 miles is considered a good return in that department!

Not sure that Jon's tires have had all that long of life. Mileage wise yes but age wise no. He will have to confirm it but I seem to recall he only got the trailer about 2 years ago??? could be wrong as time does fly. Either way your right good miles, I would be happy to get those types of miles out of an ST tire.... sadly its my experience that age gets to my ST tires life span before the mileage wear does.

[Francesca Knowles]

Originally Posted by Jon Vermilye

As to photos, I can probably do that after Sunday - they are under snow, but we are expecting a 50° day by then so maybe I can get to them.

I hope you do- I'd really like to see the wear! Do I understand correctly that it's the same on both tires, and only on the outside edge?

Originally Posted by Jon Vermilye

I'd like to replace the tires with Maxxis 8008 ST tires ......And finally, the question - Since my rims limit me to 50 PSI, and my axle weight is well under the tire pressure for the rims, is there any advantage to going to a "D" rated tire since I can't inflate more than 50 PSI?

For myself, I'd be reluctant to take a chance that someone would unwittingly inflate the tire to the maximum allowed on the sidewall, especially since it appears to be little known that rims have any PSI limits at all. Most folks just read the tire...

Also, when looking at Maxxis' chart at this link, it looks to me like there's nothing to gain by such an upfit- you get the same load carrying capacity at your 50 pound wheel limit, so no "redundancy" is achieved. And I could be wrong about this, but it's my understanding that the load ranges are indicators of sidewall strength but that there's no upsizing in tread thickness, if you're thinking of some gain in that department.

Per tire life:

As I said, yours served you very well...here's Maxxis' own much-quoted take on trailer tire life:

“The life of a trailer tire is limited by time and duty cycles,” Maxxis says. “Industry standards suggest that trailer tires should be replaced after three to four years of service regardless of tread depth or tire appearance. On average, the mileage expectation of a trailer tire is typically between 5,000 to 12,000 miles.”

Francesca

[Jared J]

flat spotted tire, grabby brakes perhaps?

[Jon Vermilye]

I did get out to photograph the tires. First I'll answer a couple of questions: They are 2 years old.
I don't think it is grabby brakes - I drive lots of gravel & dirt roads & didn't have a problem with them locking up.

The wear is on the outsides of both driver & passenger sides, although worse on the passenger side. The most worn area is at the bottom & I'm not jacking up the trailer to spin the tires! I will take better photographs and add them in the spring after the new tires are mounted for anyone interested. Again, I'm happy with the 33,000 miles I got out of the tires.

My original question was (and still is) is there any advantage to a "D" rated tire over a "C" rated tire if you are only going to inflate them to 50 PSI? I agree with Francesca that it is a bad idea to stick a tire with a stamped pressure rating of 90 PSI on a rim rated for 50 PSI unless there is an advantage to the heavier & more expensive tire.

There are more photos at 2012 Trip, Day 1 & Index, including some full size (4256 × 2832) jpgs that are around 7-8MB each.

[Francesca Knowles]

It sure looks like the load is riding the outside edge of the tire- even distribution should result in more even wear.

The pictures at least do seem similar to the "camber/toe" tire in the chart I posted earlier...since it's on both sides though a bit worse on one, my at-a-distance suspicion is that it may be related to the axle.

I guess one way to find out is to just put the Maxxis on and watch for wear patterns.

Per Maxxis replacement:

You mention "90 psi"- how big a tire will the trailer wheels hold? I didn't see any psi's higher than 65 in what I understood to be your stock size...( Maxxis Chart)

Francesca

[cpaharley2008]

If those tires were on my automobile, I'd say you had an alignment issue, camber or toe/in out issues causing the chamfer on the edges. Are Dexter axles adjustable? I do not think we ever got any info on our axles from Escape?

[Francesca Knowles]

It's my understanding that most torsion axles can't be adjusted after installation. There are some exceptions but I don't know the axle brand used here...

The funny thing is that both-sides edge wear on trailers with torsion axles is more often seen on the inside edge, and often means that the axle is overloaded. link

Don't torsion axles work partly by way of themselves flexing under the load?

It's almost as if what we see here is the opposite of overloading...as if the load isn't heavy enough to "flex" the torsion axle and level the tire.

Francesca

[cpaharley2008]

Got to eat more bread there, Jon!!! Interesting observation and use of logic there, Francesca. But on second thought, you maybe thinking of independent rear ends where the suspension toes in under light loads and out under heavy loads. With the torsion axle, I think the tire has to be parallel to the road at all times, it is just when under load the unit sits lower and unloaded, higher, but the tires remain in the same alignment.

[Jim Bennett]

I have had to get trailer axles aligned a bunch of times, especially on my work trailers that take a lot of abuse. Basically, it is done with well placed sledgehammer blows.

I take my trailer to Standens, a big name here in springs, suspensions, axles and the like. The use presses and big hammers to bring the whelks into alignment. I was having terrible problems with wear like Jon's, replacing tires WAY too often, and after starting to keep them aligned, the wear issues have almost gone away.

[Jim Bennett]

Jon, did your trailer ever take a really hard bounce at any time?

[Francesca Knowles]

Originally Posted by Jim Bennett

I have had to get trailer axles aligned a bunch of times, especially on my work trailers that take a lot of abuse. Basically, it is done with well placed sledgehammer blows.

I take my trailer to Standens, a big name here in springs, suspensions, axles and the like. The use presses and big hammers to bring the whelks into alignment. I was having terrible problems with wear like Jon's, replacing tires WAY too often, and after starting to keep them aligned, the wear issues have almost gone away.

These alignment were performed on torsion axles? That's most interesting...I've long thought that they can't be aligned once installed!

Thanks for the correction- sounds like it might be wise for Jon to get his new Maxxis from a shop that can do such an alignment, too....or take the rig to your sledgehammer guy after he gets them!

Francesca

[Jim Bennett]

My sledgehammer guy has a very delicate touch.

I was actually surprised when the shop told me that this was one method they used, they mounted some kind of alignment checking thingies to the hubs, and monitored it while the slowly adjusted. I never got to watch them do it, but just got a brief description of their methods. Whatever they did, it worked wonders, and has saved my lots of bucks in hew tires which are not cheap for that trailer.

My main construction trailer has dual 7,000 lb axles, which I take to the limit a a fair bit, but are not torsion axles. I don't know for certain, but would think the same 'massaging' could be done to a torsion axle, no?

[Francesca Knowles]

Originally Posted by Jim Bennett

My sledgehammer guy has a very delicate touch.

I was actually surprised when the shop told me that this was one method they used, they mounted some kind of alignment checking thingies to the hubs, and monitored it while the slowly adjusted. I never got to watch them do it, but just got a brief description of their methods. Whatever they did, it worked wonders, and has saved my lots of bucks in hew tires which are not cheap for that trailer.

My main construction trailer has dual 7,000 lb axles, which I take to the limit a a fair bit, but are not torsion axles. I don't know for certain, but would think the same 'massaging' could be done to a torsion axle, no?

Well...

Maybe yes...maybe no...maybe "maybe"!
That's the information I glean from the many, many hits received when googling "can a torsion axle be adjusted/aligned?"

Here's a quote from one thread discussion that pretty well sums up what I think I know about the subject:

When an axle is bent, whether from overloading or a hit that affects one wheel, it is the spindle that is out of line. Think metal clothes hanger. Bend it once, it weakens it, bend it numerous times and you can snap it. If the tires on wearing on the inside, the spindles are bent up, usually from overloading. If the tires are cupping and scuffing, the spindle is usually bent forward or backwards, resulting from a blow like hitting a curb, chuckholes on a corner, etc. We find this kind of damage usually on the right front wheel.

We replace quite a few axles every week, both spring and torsion style. We have very rarely encountered axles that were "out of line" due to the placement of the hangers or the attachment of the torsion axle brackets. If that is the case, the only way to align those axles is to remove them and put them on correctly.

It's also my understanding that much depends on the brand of axle and the way it was installed. Flexirides, for example, have some adjustments and replaceable spindles/rubber, while Dexters do not....and welded on is harder to service than bolted on.

Francesca