Pneumatic radial tire

摘要

A pneumatic radial tire has as a reinforcement for a crown a belt consisting of a plurality of laminated plies whose cords intersect to each other. A coating rubber having a higher modulus is applied to the central zone of the belt which would be subjected to the most of the vertical stresses caused by the inner air pressure when the tire is inflated, and a coating rubber having a lower modulus is applied to the edge zones of the belt. The lower modulus coating rubber has a high elongation and a high tensile strength at break which serve to reduce shearing strains at the edges of the belt. Such coating rubbers having different properties are used in central and edge zones of the belt to match the requirement of the strengths of the belt, thereby increasing the service life of the tire.