REDUCED ROLLING RESISTANCE PNEUMATIC RADIAL TIRE

摘要

A heavy duty pneumatic radial tire includes a carcass consisting of at least one layer of metal cords substantially radially arranged, a breaker consisting of at least two layers of metal cords to form a main reinforcement with the carcass, and bead portions including hard and soft stiffeners. The carcass has a particular radial profile having a ratio of radii R/R' determined by a radius R' of a standard circle and a radius R determined by a particular definition and has a maximum distance f between an arc of the standard circle and the remaining carcass line smoothly extending from the profile curvature of the shoulder. Moreover a radial profile over a radially inner zone of the sidewall of 20-45% of the radial height SH has a curvature 1/ rho less than 6x10-3 mm-1 at a location 32.5% of the radial height corresponding to a center of the profile.