Abstract: An open-torus radial ply pneumatic tire is configured for mounting on a specially designed rim. The special rim includes means for restraining the radially outward movement of the tire's rim securing regions, which are spaced apart regions of the rim in which the tire's radial carcass plies are anchored. In the rim securing regions, the carcass plies are turned axially outwardly and encased in a molded elastomeric material having a shape complementary with that of the restraining means of the special rim. The tire also includes a belt structure positioned radially outwardly of the carcass plies.