| 摘要 |
<p>A pneumatic radial tire comprises a radial carcass, a belt, and a row of many blocks (5) having different lengths along a circumference of a ground contact region (1) under pitch variation defined in a tread rubber of the tread portion by at least two straight main grooves (2,3) and a plurality of lateral sub-grooves (4) extending between the mutual main grooves at an inclination angle of less than 90 DEG with respect to the circumference of the ground contact region, in which the block row satisfies such relationships that an inclination angle ϕL of an edge of a long-pitch block is larger than that ϕS of an edge of a short-pitch block and an inclination angle alpha L of each block wall face of a long-pitch block is larger than that alpha S of each block wall face of a short-pitch block, and/or further an inclination angle beta S of a block wall face of a short-pitch block is larger than that beta L of a block wall face of a long-pitch block. <IMAGE></p> |
