Re: Radial vs Bias ply tires
The steel belt in the tread makes radial tires track true without squirm. The radial sidewalls give them better spring and lower running temperature than bias sidewalls. Because the side give is linear and not a squirm, the radial tires tend to track truer and corner better. Because they run cooler, they are less prone to blowout than bias ply tires. Because they don't squirm, they are more sensitive to misalignment, but will have better tread life than bias tires if the alignment is true.
Excessive wear is usually caused by alignment. The heavier they are loaded, the worse the wear will be. If there is more wear near the sides than in the middle of the tread, they are either overloaded or underinflated.
I once borrowed a single axle utility trailer I put a decent set of tires on it. I put a reasonable load in it, and hit the road. 1100 miles later, in the middle of the night going around Flathead Lake, Montana, one of the tires got to end of life and blew. The trailer pulled normally, I thought, but it was out of alignment. Because I was in Montana, in short order I had more help than I could use to change the tire.
A good alignment shop should be able to deal with trailer wheel alignment, with the load on the trailer. They may need to bend the axle tube to get it right, but they have the tools for it. There may be issues with spring pin wear or other suspension components. If the axles are too light, or cantilevered too far from the spring for the load, they may not align, but you will know where the problem is.
hope it helps
John
