What tire mfg. is best at sidewall crack prevention?

As an aside – I always wondered if one should be majorly concerned about some sidewall cracking, since tires have several belts of steel and polyester on the sidewalls. After all it’s the belting sandwiched between the rubber that gives all the strength isn’t it? So if some cracks appear on the sidewalls even if near the beads – you still have those belts under the rubber - plus the wire inside the tire beads.

Is not the rubber bonded to the belting on the sidewalls?

I have really never seen this discussion anywhere relating sidewall cracking to the sidewall belts...all I read is OH better run out and replace tires right away if there are cracks in the sidewalls!

j-d wrote:
Just be careful they are in fact Light Truck (LT) series since that size is also available in Passenger (P) series. So you're shopping for LT225/75R16E.
Because a "D" tire will handle the capacity of your chassis, replacing with "E" will give you a tougher tire. That's why I don't think you need to go with commercial-duty tires like many of us with 29-32-foot Class C's have done.

Thanks,

OK so are you saying that a P225/75R16 could be used instead of the LT tires? P225/75R16 instead of the LT225/75R16 Lond Range D's?

j-d wrote:
... So you're shopping for LT225/75R16E ...

BTW, LT215/85R16E tire size is OK too. They have the same load carrying spec ("Load Range E" is "Load Range E"), but have a slightly larger diameter for improved ground clearance and maybe slightly improved gas mileage due to making the vehicle's overall gear ratio a bit taller.

I recently put six(6) new Michelin LTX215/8516E M&S2 tires (plus the spare) on our Class C and they have so far been superb. I hope and trust that the sidewall cracking will no longer occur. I use 303 on them just in case because the tire covers are a hassle (started to move the RV in the back yard twice in the past without removing the covers and hence tore them up!).

IMHO, sidewall cracking is much more related to the excessive heat generated from sidewall flexing on the highway while traveling with slightly too-low inflation pressures per the weight they're carrying (this is regardless of weight chart numbers because weight charts are not concerned with maintaining a tire's shape under load). I have noticed that big rig tires never seem to have any apparent bulging in their sidewalls when you take a look at their tires at rest stops because ... they are fully inflated at high pressures so as to keep their shape to provide minimum flexing regardless of load.

Even though I have a small Class C that nicely underloads it's Load Range E tires, I still keep the rear tire pressures at their maximum Load Range E rating of 80 lbs.. This makes the ride in the rear stiffer but minimizes heat generation in the sidewalls. Also, since a 215 tire is slightly narrower than a 225 tire, there is better air circulation between the individual tires in rear dual sets for further improvement in removal of the heat resulting from sidewall flexing.

BTW, with 80 lbs. pressure in the rear duals, Michelin's new M&S2 sidewall material still does manage to somehow improve the ride a bit in the rear of our Class C. My future addition of Koni FSD shocks in the rear should help even more.

The "Ply Rating" is that, a rating not a construction detail. Back in the days of fabric bias-ply tires, "Eight Ply" was a heavier duty tire for 3/4 and one-to trucks. Possibly to get away from questions like yours, they've adopted Load Range to replace Ply Rating. The Load Range can be achieved various ways.
65PSI confirms you have Load Range "D" tires now, so it's a 3500 (or 350) "One-Ton" (another term hard to relate to actual carrying capability) chassis. The 450/4500 is "Ton and a Half" and requires Load Range "E."
You'll have to go out of your way to find tires in your size that are not "E" since there's no penalty for using them in place of "D" meaning why stock them. Just be careful they are in fact Light Truck (LT) series since that size is also available in Passenger (P) series. So you're shopping for LT225/75R16E.
Because a "D" tire will handle the capacity of your chassis, replacing with "E" will give you a tougher tire. That's why I don't think you need to go with commercial-duty tires like many of us with 29-32-foot Class C's have done.

The best way to prevent tire from cracking is to cover them when ever your going to be parked for extend time!

carringb wrote:
I'm nor sure there is a brand that is less crack-prone that others. Your best solution is applying 303 or other UV inhibitors, and covering the tires when parked.

And then again, I had the same set of Cooper tires on my 4X4 pickup for 12 years or so uncovered with no 303 on them (...and I even occasionally put the El-Cheapo black shiny stuff on them so they would "look good") sitting out in the CA sun and they never had any sidewall cracks at all - the tread finally wore out. Go figure.

I'm hoping beyond hope that the seven new Michelin LTX M&S2 tires I recently put on our Class C don't develop sidewall cracks. The M&S2 sidewall ply material has been changed to some high-tech sounding material so maybe Michelin did their homework on sidewall cracking.

I don't believe that steel sidewalls have anything to to with it and steel sidewall commercial tires usually come with only a fairly smooth highway tread. IMHO, a M&S type tire tread is ideal for an RV so as to be ready for any reasonable road surface condition at any time, anywhere.

I'm nor sure there is a brand that is less crack-prone that others. Your best solution is applying 303 or other UV inhibitors, and covering the tires when parked.

Yes it shows 65 PSI on the side walls.

On the ply rating - interestingly the sidewall states that the tire has two steel belts and two polyester belts on the sidewalls. But you say Load D is 8 belts and I saw that somewhere else on the net so I am not sure why my tire sidewall states only 4 belts total.

Yes, "S" means 112MPH. 110 means 2337# and 107 means 2149#. That means your Front Tires can carry up to 2337, and each rear dual tire can carry 2149. Tires are rated to carry a little less in the dual application than the single.
What Max Air Pressure does the Sidewall show? My guess would be 65PSI meaning Load Range "D" which is the old "8 Ply Rating". Most of the tires in your size sold now are at Load Range "E" or 10 Ply. You may hear them called E-Ten and that has nothing to do with Ethanol in your fuel tank. Go ahead and get E-Ten. You won't increase the capacity of your chassis but you'll have tougher tires. Weigh your coach and see what your axle weights are. I think you'll find you're in the D-Eight range and any quality Load Range E (E-Ten) tire will please you. I just this week installed new Bridgestone Duravis 250 tires which are a commercial duty tire. I did it because our axle loads are very close to max for this tire size even in E-Ten. The Michelin XPS Rib is another tire in that category. If I had a lighter coach, which yours should weigh out to be, I would look hard at Firestone TransForce. The Michelin LTX M/S2 would be a step up. Excellent comments on both of these. Michelin LTX used to crack but the impression is that it's been corrected on M/S2.

Yokohama