Atlee wrote:
Thanks for your reply.
I don't understand this paragraph so much. I do understand that we aren't talking about static load, that while pulling the TT, forces will apply more that the static load on the tires. However, it seems like the 42% margin I have, 7040# weight load for the tires, compared to the 4950# GVWR of the trailer, I should have enough margin for the non static forces on the tire.
Also, you mentioned 85mph. I do not do 85mph in my trailer. I don't do 75mph with my trailer. I drive between 60 and 65 mph, or the speed limit, which ever is lower.
That said, on a few occasions I could get above 65 if I were forced to pass someone. I like to get by as quickly as possible.
And I will not put another 10 psi in any Marathons I own, in order to drive 75.
I wouldn't drive 85 mph in my Fusion which has Michelin Pilots with a very high speed rating.
CapriRacer wrote:
Atlee,
And lastly - doing the math: You may think 4950# is well away from 7K - BUT - if we consider side to side and front to rear weight variation and a 15% un-used over-capacity, AND factors to raise the speed limitation to 85 mph, then the axle loads need to be less than 7900# - which is well over what your trailer is capable of handling. I think trailer manufacturers have a role to play in this as well. They need to provide tires of adequate size to cover ALL the things that make for good tire performance.
A corollary might be, "would you run your engine constantly, all day long at redline? "
ST tires are speed limited ( redlined ) at 65 mph.
I suspect the answers to your original question lies in something Barry said ( design and possibly older production equipment ) regarding problems in ST tires, and I agree also fla-gypsy's comment about chinese production.
So I go back to what I have said in other threads on this subject: I do not buy ST tires. I do not buy chinese tires. A chinese ST is a double whammy, so there is no way at all I would buy them.
I use LT tires.
For what it's worth, TireRack will have tires to you in a couple of days. I'm sure there are other online tire dealers that could ship just as quick.
I would replace your valve stems with metal stems and have them balanced.
