The 7 year old Maxxis tires are shot, starting to break apart in the ribs. I have had great luck with these, wondering about the New (to me anyway) Goodyear Endurance tires made in the US and seem to ...
The Endurance is built just like any fabric carcass P/ST or LT tire with two polyester carcass (body) plies and 1 or 2 nylon caps under the tread plus the usual 2 steel tread belts.
The Sailun S637 has a all steel ply carcass plus the twin steel tread belts. Its intended for regional trailer service work and also rv trailers.