My opinion is to use them. I know guys with radials run quite a bit more air pressure than a bias ply so that helps keep the bead intact. I run 14.5 x 33's @ 6.5 pounds and they grow at least 3 - 4 inches at speed. For $14 at RJ race cars, I put new (32) screws in each rim at every slick replacement. Slick never moves on the rim and I run no tubes. This is for my piece of mind and my safety.