Tire ply

[kaweeka]

Replacing main tires I have the choice of 4-ply vs. 6-ply. Aside from the number of plys, is there a clear preference for the main tires on the -9A?
Thanks,
David

[n82rb]

In modern tires the ply rating does not indicate the number of plys anymore. It just a rating. Generally the higher the rating the more load the tire will take. There is no reason to put more that a 4 ply on an rv.

Bob burns
Rv-4 n82rb

[Ralph Inkster]

Vans supplies 6 ply with their kits. Gives you some extra load factor & stiffer tire side walls. You should consider the tire sideways movement & squash rate with the softer sidewalls & how it may work with tight fitting wheel pants.

[rvbuilder2002]

Originally Posted by Ralph Inkster

Vans supplies 6 ply with their kits. Gives you some extra load factor & stiffer tire side walls. You should consider the tire sideways movement & squash rate with the softer sidewalls & how it may work with tight fitting wheel pants.

Very good answer!

[kaweeka]

I read previous posts and came to the conclusion that the 4 ply would be adequate but was concerned that any "forgiveness" that would provide in a softer ride might impact the clearance with my wheel pants. Your posts reinforced that thought. thanks you for answers.

[DanH]

Originally Posted by n82rb

In modern tires the ply rating does not indicate the number of plys anymore. It just a rating. Generally the higher the rating the more load the tire will take. There is no reason to put more that a 4 ply on an rv.

Depends on the weight of the RV. The load ratings say a 5.00-5 4 ply is fine on a 3, 4, or 12. A 9 at 1750 is marginal. A 7 or 8 at 1800 slightly exceeds the ratings for a 4 ply tire.

In my opinion, 7's, 8's and 9's should get 6 ply tires and run 45 psi minimum. Why? During a 3G+ bounce at 1800 lbs and 45 psi, the tire will compress very near flat, i.e. the bead will be close to contacting the inside of the tread carcass. Pity the poor tube. The actual compression will vary with variation in leg stiffness.

Same load at 31 psi (max for a 4 ply tire), and you're way past smashing the tire flat to the rim.

http://www.vansairforce.com/communit...4&postcount=37

Somebody will now post that they've been flying 4 ply tires on their heavy RV for years without a problem. Fine, no argument. As long as they always land gently, and always maintain full rated pressure, they should not have a problem.