Happytrails

John, I believe the speed rating on the tire is because trailer tires are made of a different type of rubber. They are designed specifically what they're for......trailers, which spend a lot of time sitting. The special compound they're made of is made to resist the effect of sitting in one place for long periods of time. They also are designed to resist the effects of ultraviolet light better than regular tires, (I think). I believe the tires on mine are really old, but they're not cracked or dryrotted in any way. I'm probably going to replace them anyway before I put it on the road just for safety's sake.

Happytrails......