Patent ID: 7093630

Claim:
A heavy duty radial tire comprising a tread portion with tread edges, the tread portion provided with traverse grooves extending between the tread edges and longitudinal grooves extending between the traverse grooves so as to form shoulder blocks arranged along each of the tread edges and inner blocks each disposed on the axially inside of one of the shoulder blocks, the longitudinal grooves between the shoulder blocks and the inner blocks, having a depth Dga and a width Wga, the depth Dga being in a range of from 0.7 to 1.0 times the depth Dy of the traverse grooves, and the longitudinal grooves each inclined at an acute angle with respect to the circumferential direction of the tire to have an axial extent range Y whose axial width W 1 is in a range of from 1.0 to 10.0 times the width Wga, in a cross section of the tire under a normally inflated unloaded condition: the tread portion provided with a tread profile made up of a center profile Si and a shoulder profile So, the shoulder profile So extending continuously from each of the axial ends of the center profile Si through an inflection point P to one of the tread edges; the center profile Si being a circular arc of a radius Rc having the center on the tire equatorial plane; the shoulder profile So being a substantially straight line or alternatively an arc having less curvature than the center profile Si; and the inflection point P located within the axial extent range Y of the inclined longitudinal grooves so that on the tread face the inflection point describes a circumferentially extending straight line crossing each said inclined longitudinal groove.