Tires

[Francesca Knowles]

Did you guys really miss the point of Michelin's description of correct design for (any size) tires on axles other than drive/steer, or are you just pulling my leg? I ask because that leg gets pretty numb after awhile, so it's hard to know...

Francesca

[Brian B-P]

Originally Posted by floyd

BTW,Am I to assume that Michelin wants you to decrease pressures at the unloading dock and increase them again at the loading dock?

As anyone who read the referenced material knows, the answer is no. Neither does your car or pickup truck manufacturer suggest changing the tire pressure every time a passenger gets out or in.

Originally Posted by floyd

... Fleet tires are set at least to the maximum expected load plus a margin up to the maximum sidewall pressure.

Right... not simply to the sidewall maximum. Again, just like your car or pickup truck, for which the manufacturer directs the use of a pressure sufficient and appropriate for that vehicle, allowing for operation at its maximum load... not the tire sidewall maximum unless the vehicle's allowed axle load requires that much pressure.

[Brian B-P]

Originally Posted by Francesca Knowles

Did you guys really miss the point of Michelin's description of correct design for (any size) tires on axles other than drive/steer...

Nope, didn't miss that, any more than I missed the need for my minivan to have different designs of tires on the driving and steering front than on the non-driving and non-steering rear.

[Brian B-P]

Originally Posted by floyd

Heck, I'm so dumb that I see differences in P metrics among different profiles, brands, and compounds.

So, do you assume that, since there are these differences, that a car must use only the brand and model of tire that it has from the factory? My guess is "no".

[Brian B-P]

Originally Posted by ruscal

Radials by design seem to be laterally soft which may not be desirable for a trailer.
...
The big truck michelins are often a lot wider than conventional tires which may provide some lateral stiffness. They take the place of duals in some cases. Most of the concrete trucks around here use them.

Most commercial truck tires are still the traditional tall-and-skinny proportions; they are used singly on steer axles and in dual pairs on drive and trailer axles, are of radial construction, and have no lateral stability issues. The classic common size for the biggest highway trucks is 11R24.5, which has the proportions of a common ST tire... just almost twice as large in every dimension. When I stop in traffic beside a big truck I often look at the tire size - I can't remember the last time I saw a bias-ply tire on either truck or trailer (brands other than Michelin are also radial).

There are some wide (low profile, e.g. 65-series) tires usually called "super singles") that are mostly used on steer axles and castered pusher and tag axles for higher capacity; they are very common on the front axles of dump trucks and those concrete mixer trucks. Less commonly, there are very wide (very low profile, e.g. 50 series) commercial tire sizes now available (usually called "wide base" tires) to replace a conventional dual pair with a single tire; they are on drive and trailer axles. Radial construction may have made these tires more practical, but is certainly not restricted to them.

[gmw photos]

There. Tired of arguing with you guys and gals. Ha ! ....put that on your little fiberglass trailers....see if you can hurt this one......

[Thomas G.]

Originally Posted by gmw photos

There. Tired of arguing with you guys and gals. Ha ! ....put that on your little fiberglass trailers....see if you can hurt this one......

225 mph ...... ........ Yea, that will do.

[carlkeigley]

I've done 95 in semis and been passed by other semis like I was sitting still.
Very late at night of course.

I prefer to stay at 75 or below in a semi.
Otherwise you need at least a quarter to stop.

[gmw photos]

Originally Posted by Thomas G.

225 mph ...... ........ Yea, that will do.

...yes sir. And 46,700 pounds capacity per tire ought to hold it up too.....

[floyd]

Originally Posted by carlkeigley

I've done 95 in semis and been passed by other semis like I was sitting still.
Very late at night of course.

I prefer to stay at 75 or below in a semi.
Otherwise you need at least a quarter to stop.

But I 'm saving my quarter to get a cart at Aldi...
Could I stop on a dime if I just go double nickel?
Makes cents to me!

[Carol H]

Awesome find George!!! You sure made my next tire purchase easy!

[gmw photos]

Very interesting discussion going on regarding tire failures. The photos and discussion are informative:

RV.Net Open Roads Forum: Towing: Unsafe at any speed....

[Thomas G.]

Originally Posted by gmw photos

Very interesting discussion going on regarding tire failures. The photos and discussion are informative:

RV.Net Open Roads Forum: Towing: Unsafe at any speed....

From this link:

Yesterday I was outside, and I heard a loud "bang", and I walked over to the trailer and the spare tire had exploded. See photos below. The spare tire had only been used the one time when the Hercules tire blew out in California, and had a total of 50 miles on the tread. The Towmax spare tire has always been covered and was inflated to 65 pounds. It was not hot, it was about 75 degrees.

Boy, what a nit picker.

[gmw photos]

Originally Posted by Thomas G.

From this link:



Boy, what a nit picker.

Yeah, imagine if that would have happened as he was getting ready for bed in the evening ! That would get your attention.

[Thomas G.]

Originally Posted by gmw photos

Yeah, imagine if that would have happened as he was getting ready for bed in the evening ! That would get your attention.

Or in the middle of the night.

[Brian B-P]

Originally Posted by gmw photos

Very interesting discussion going on regarding tire failures. The photos and discussion are informative:

RV.Net Open Roads Forum: Towing: Unsafe at any speed....

Great link. As with all such discussions, all information is a little bit suspect. One responder posted that

I had about 10 LT Michelins that did the exact same thing.

... but he later posted a photo of one of these "LT" tires, which is actually a P tire (P235/75R15). I wonder if he also forgot to mention overloading them?

Although the original poster seems very diligent in providing information, and even reports actual total axle load, I didn't see an indication of individual axle loads, so we don't know if there was a problem with unequal loading. Some information is only implicit: the original tires were presumably Load Range D (based on the reported 65 psi inflation pressure limit). Despite these detail issues, it certainly does seem like he got some Super Trashy tires.

I would be concerned by a tire exploding while not even in use, too!

[Steve L.]

Another thing about dual axle trailers is that if one tire fails (perhaps a puncture) that usually means the other tire on that side is instantly overloaded and when/if the companion tire fails, some pretty severe side loads occur on the other end of the axle making those tires suspect as well. Tires don’t heal. Heat and stress that reduce tire life is tire life that is gone forever. Getting the trailer safely stopped promptly is key to not overstressing the other tires.

[Stretcher]

Has anyone had a comparative experience between running radial tires with 50psi max rating versus 65psi max? The 65s seem to offer a higher load rating. Are there any downsides to the 65s? We're about to purchase a pair of ST175/80R13D tires. Where will I find the max pressure rating on our wheels? If I can't find it and decide to go with the 65s, we'll probably buy pre-mounted wheel and tire from etrailer. The tires Scamp installed are 50psi max, so I'm guessing our wheels are as well. We haven't found any 'D' rated tires locally.

Thanks,
David