Re: How fast do you tow?
I found this on etrailer.com regarding the speed rating of small trailer tires:
I've towed all over NJ with 8" tires, and even further a few times and never had a failure, but I rarely hammer down on the gas when towing a small tire trailer. A number of years ago I had a trailer on which one day I noticed tire marks on the inside of the fenders, which were at least 2" above the tires. The tires were new, Goodyear 4.80x8" tires, the fenders attached to the axle not the frame on this particular trailer, so it wasn't a matter of travel. What was happening was that at high speeds, the tires would 'grow' enough to hit the fenders. This happened at lower pressures, not so much at higher pressure too.
If I ran the tires at their max pressure, I got no tire marks or rubber on the inside of the fenders, but would get tire marks and burnt rubber at higher speeds if I ran the tires at what I thought was enough air for a light boat. I was running them at 45psi, and they would grow and hit the fender, but not if I put the full 80psi the sidewalls called for. Through it all, I never had a blow out. Even running up and down the parkway or turnpike here.
I still have a few trailers running 8" tires, I never worry about them blowing out, but do make sure their in good shape before any trips. I stay with the smaller tires since it keeps the boat lower and easier to launch.
I find that with a small aluminum boat in tow, and a light trailer, much over 65mph is too fast as the boat's shape gives the trailer some lift and makes it a bit unstable. I've pulled my larger boats faster with no issues though.
The more modern trailer tires do seem a lot better than the bias ply tires of the past, and all it takes to keep a tire together is some common sense. Keep the air pressure up, and when their dryrotted, replace them.
I get about 5 years out of a set of tires, regardless of miles, they seem to rot away long before they wear out. For those running smaller tires, 12" and under, keep in mind that their bias ply tires and even back when we all used bias ply tires on our cars, 10,000 miles was about all the miles you got from a tire, so I figure that if I get a couple of thousand miles and a few good years out of them, I'm happy.