Tire and rim

A pneumatic tire of the open-torus type and rim assembly, the tire being configured for mounting on the rim assembly, the rim assembly including means for restraining the exterior of the tire at its portion forming the circumferential opening on the radially inner side of its toroidal form, thereby, to restrict radially outward movement of the portions of the tire accessed by such restraining means, the tire comprising:

• (a) one or more radial-cord carcass plies extending between two axially spaced apart rim securing regions, the carcass plies in each rim securing region being folded axially and radially outwardly about an annular tensile member and being encased in an elastomeric material, the elastomeric material at the radially inner side of the tire being molded in a shape complementary with that of the restraining means of the rim assembly, thereby, to permit the rim restraining means to restrict radially outward movement of the rim securing regions of the tire engaged from its exterior by the restraining means of the rim;
• (b) a belt structure positioned radially outwardly of the carcass plies, the belt structure having axially outermost edges and in one or more plies, cords oriented at both positive and negative angles with respect to the equatorial plane of the tire, the angles being in the magnitude range from 17.degree.-30.degree., the belt structure providing circumferential restriction of the inflated tire profile;
• (c) a tread positioned radially outwardly of the carcass plies and belt structure;
• and
• (d) a sidewall having a flexible sidewall portion adjacent the rim for primary sidewall bending, a stiffer portion radially outward of the flexible sidewall portion, and a thinner cross sectional portion between the stiffer sidewall portion and the outermost edges of the belt structure.