Another Tire Question

[gmw photos]

Jon,
As for replacing the tires with LR D tires, I know what I would do if it were mine. I'd replace the wheels to gain a wheel with a higher psi capacity, then buy the appropriate LR D tires. I personally would 'for sure' do this on a single axle trailer. With only two tires on the ground I'd want all the extra capacity I could get.
Wheels don't cost all that much. I'd also use metal valve stems.

george

[Jon Vermilye]

Originally Posted by Francesca Knowles

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

Yea, you are right - 65 PSI is the max. As to a "hard bounce" I have to admit a yes. I suspect I should get an alignment check with the new tires, although I don't know anyone in the area that I'd trust to align a trailer...

[Jared J]

My trailer did that on one axle. A straight edge, chain, and bottle jack fixed it.

Any axle can be aligned, it's a matter of how much work.

[Francesca Knowles]

Originally Posted by Jared J

My trailer did that on one axle. A straight edge, chain, and bottle jack fixed it.

Any axle can be aligned, it's a matter of how much work.

Would that be the same car hauler trailer you had all those blowouts on, Jared?

Francesca

[Jared J]

Jared, and yes, but I got the trailer that way. All the blowouts were after it was fixed, and not all on that axle.

[Francesca Knowles]

Originally Posted by Jared J

Jared, and yes, but I got the trailer that way. All the blowouts were after it was fixed, and not all on that axle.

Well, it's a novel way to fix a torsion axle, that's for sure!

O.K. if Jon swings by so the "doctor" can have a look at his?

Francesca

[Jared J]

Pretty easy. Find out where it's bent, attach a chain to the "low" spots, put the bottle jack on the "high" spot with the chain over it, and start jacking.

I thought I had a picture of me straightening an axle I was trussing, but I don't. Here's one I stole from somebody's photo bucket.

[Marv Watson]

The wear shown in your pictures looks similar to what I experienced on 2 sets of tires that only lasted less than 15,000 mi. each. I cured the problem with a new axle. Current tires have in excess of 15,000mi. and still look great, with even wear.

[Francesca Knowles]

Originally Posted by Jared J

Pretty easy. Find out where it's bent, attach a chain to the "low" spots, put the bottle jack on the "high" spot with the chain over it, and start jacking.

You know what, Jared? You're one of my favorite guys!

And I mean that.
Your do-it-yourself spirit is really admirable, and, frankly, getting to be a bit on the rare side these days. It's nice to find that there are still mechanical generalists out there. Sometimes it seems that the breed's dying out...keep it up, and keep on posting!

But I'm not sure Jon should do-it-yourself this one... that's a pretty new rig, and from what I understand possibly still under its original warranty. (Two years per recent post by Jim). It would probably be best for Jon to consult the makers of both the tire (for diagnosis of wear pattern) and the trailer before he starts whangin' away on the axle...

Francesca

[Alf S.]

Hi: All... I remember looking at Jon's tires at Niagara Wine Escape and I noted the bad spots were on the opposite side to the weights. If the wheel bearings had been repacked and the wheels not put back in the same local... could be responsible IMHO but I'm no tire guy!!!
Alf S. North shore of Lake Erie

[Brian B-P]

Originally Posted by cpaharley2008

But on second thought, you maybe thinking of independent rear ends where the suspension toes in under light loads and out under heavy loads.

Many independent suspension designs - front or rear but especially some simple designs used in the rear (or on trailers) - change both camber and toe significantly with vertical travel, as well as changing toe with drag force.

A common design is the semi-trailing arm, which (as explained in an article about BMW suspension) toes in and cambers negative under increased load, and toes out and cambers positive under decreased load... before considering any bushing deflection effects.

Originally Posted by cpaharley2008

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.

The independent "rubber torsion" designs available in North America are fully trailing (or leading) arm configurations which ideally do not change camber or caster with travel; however, the non-moving structural beam bends under load, and the rubber distorts as well, so the beam is routinely pre-bent slightly, to produce the desired alignment when it bends under load.

[Jared J]

Originally Posted by Brian B-P

The independent "rubber torsion" designs available in North America are fully trailing (or leading) arm configurations which ideally do not change camber or caster with travel; however, the non-moving structural beam bends under load, and the rubber distorts as well, so the beam is routinely pre-bent slightly, to produce the desired alignment when it bends under load.

Excellent point. If axle beams are bent up slightly in the center, it's probably supposed to be. If they're bent down, they're bad or upside down. This is
usually caused by somebody "flipping" a cambered axle from over the spring to under it, without welding new mounts on the other side. If they're bent front to back, also bad.

[Raz]

Originally Posted by 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.

Jon, if I had that wear pattern on two tires I would suspect something is wrong, most likely the axle not the tires. I would post this on the Escape forum to see if anyone else has had the same experience. I would contact Escape with pictures to see if they had any experience with this in the past. They will also know the particulars for the axle. I would call Dexter, talk to one of their experts and send pictures directly to that individual. Dexter will know if there is a problem and should be able to direct you to a shop in your area that can do repairs if needed. I suspect it will be a spring and chassis shop. It could be that this is normal wear for that axle with that brand of tire, but it's best to find out. Raz

[Francesca Knowles]

Meanwhile, back at the other part of Jon's question:

Anyone else care to weigh in as to whether there's any benefit/reason for him to go to a higher load range tire? C's are stock on the trailer and he's contemplating going to D's. He does say that his rims are limited to 50 PSI max.

Francesca

[baron100]

The two extra plies that the "D" tire affords would be my choice. The marginal cost for this protection would be well worth it in my opinion. Your trailer experiences loads on it when traveling that are much greater than the static loads for the weight of the trailer. There is no penalty for using a higher load rated tire.

[Jon Vermilye]

Originally Posted by Francesca Knowles

Meanwhile, back at the other part of Jon's question:

Anyone else care to weigh in as to whether there's any benefit/reason for him to go to a higher load range tire? C's are stock on the trailer and he's contemplating going to D's. He does say that his rims are limited to 50 PSI max.

Francesca

Well, as to the tires, Maxxis are not available locally, and Discount Tire Direct, one of the few internet suppliers, only carries the "D" tire so I'll probably go with them. $231.54 for the pair, no tax or shipping...

[Francesca Knowles]

O.K.!
Presumably you've already inquired of whoever your installer will be as to whether they'll install the 65 max tires on a 50 PSI limited wheel.

After the install's done, you might consider writing the lower PSI limit on each wheel/tire somehow so as to prevent some future airer-upper from overfilling the tire...

Good luck!

Francesca

[Brian B-P]

Originally Posted by baron100

The two extra plies that the "D" tire affords would be my choice. The marginal cost for this protection would be well worth it in my opinion.

I don't know what the protection would be from. Overinflation? If you don't inflate to the higher pressure (which the wheels would not allow in this case), the LR-D tire has no more load capacity than the LR-C tire (at the same inflation pressure).

Originally Posted by baron100

Your trailer experiences loads on it when traveling that are much greater than the static loads for the weight of the trailer.

Yes, and the tire construction standards account for that. The capacity rating is for the weight carried in use, not the maximum amount that can be held up in a simple static situation.

Originally Posted by baron100

There is no penalty for using a higher load rated tire.

The unnecessarily higher-rated tire is heavier, probably more expensive, less compliant (and therefore has less traction), and may build more sidewall heat due to resistance to flexing. Those are penalties, although they may not be significant - I run Extra Load winter tires on my car (like a Load Range C compared to the Standard Load normal tire which is like a Load Range B ), only because that's the way the desired model comes in my size, and they work fine.

[baron100]

Tires, always a festive discussion.

A couple more thoughts on tires. (okay, I ended up with more than a couple).

Most of us have single axle trailers. A failure of either tire could result in a catastrophic accident. Replacing a tire at the side of the road by itself presents significant risk to the owner while changing the tire. Think I-405 in Seattle at rush hour.

The single most important safety decision we make as trailer owners is in tire selection. The travel and boat trailer forums are replete with pictures of mangled tires and damage to trailers from tire failures. Often owners report multiple failures.

In a recent Casita event, an owner experienced loss of trailer and tow vehicle and thankfully was able to get her daughter and granddaughter to safety in time. Another owner reported multiple thousand of dollars repair due to a tire failure. It is disconcerting to me that this trend seems to continue even though a solution to many of these failures has been identified for years.

Buy the best tire you can put on your trailer and keep it properly inflated. The marginal extra cost is minimal when your safety is considered. A higher load range selection in a tire that supports your trailer's weight is better for your safety and longevity of the tire and maybe yourself.

"In approximately three years, roughly one-third of the tire's strength is gone." Discount Tires. (The largest independent tire distributor in the USA since 1960). Travel trailer longevity has little to do with wear on the tread thickness of the tire and more to do with the cycles (miles) you put on them. The tire will often be "worn out" without much external external wear.

Fact is, the trailer manufacturers have scrimped on the original tires they provide their customers. Yes, the tires they provide may marginally support their trailers on paper when they come out of their factories. The many failure encountered, often after minimal miles, is suggestive that they are not adequate. This seems to be even more noticeable for those that operate their trailers in a high heat environment like Arizona and Texas in the summer time.

In Jon's example, he is pulling what many consider the highest quality fiberglass trailer made. He travels extensively across the country. Why compromise on tire selection?

An extra two plies of tire construction affords him additional protection in the form of reduced risk of tire penetration from a foreign object (a leading cause of failure after under inflation) and is a tire of much greater strength.

A selection of the "D" rated tire and keeping it inflated to 50 PSI, by the recommended load charts, supports up to 3,640 lbs on the axle. Since inflation is more than required for his stated 3,025 lb trailer, sidewall flexing would be less and the tires would run cooler.

The "D" range tire also will be a better choice given "In approximately three years, roughly one-third of the tire's strength is gone."

Consider one other point. Many trailer manufactures scrimp on the axles they chose. A loaded Casita SD (and many other brands) trailer is very close to the max 3,500 lb rating the Dexter axle provides, leaving minimal margin. It is reasonable to assume that the additive tension resulting from the axles stressed to the maximum causes additional stress on the tires.

Given, the above, I believe that Jon has right sized in his choice of tires and in fact will not be purchasing more tire than he needs.

I was told by many that I had over killed my selection of Maxxis M8008 ST225/75/15 tires for my Casita. I run them at 80 psi, so they run cooler and can handle the maximum loads the trailer experiences when traveling down the road.

I replaced the first set at 32,000 miles with new ones and they looked almost identical to the old ones. No cupping or irregular wear as I was warned. If they "bounced" down the road as I was warned, it was not evident to a fellow traveler that followed me for 5,000 miles.




Safe Travels,

45,000 miles on Maxxis "E" rated tires from Canada to Mexico without a failure.

[cpaharley2008]

Good advice and that is the way I'm going...