The whole RV industry is being bombarded by substandard Chinese ST tires. Tire companies simply will not produce enough high quality tires for trailers to meet demand at a reasonable price.
For example, the Goodyear 124's will set you back $399 apiece--ridiculous.
The whole ST tire industry should be subject to U.S. Government performance standards, like the auto industry, or those tires should be prohibited.
I just get tired of reading (on RV forums) about RV's tires blowing when they've got little or no miles on them. And when tires blow, they take out fenders and siding causing substantial damage. It doesn't have to be this way.