| 摘要 |
PROBLEM TO BE SOLVED: To provide a pneumatic radial tire maintaining right weight and high speed durability and improved in the damage resistance in a bottom of each groove. SOLUTION: Surface-inside bending rigidity of a tread part 16 is obtained by an inclined belt layer 20 formed by arranging plural steel cords extended while inclined in relation to the tire equatorial surface CL so as to withstand the lateral force when cornering. Circumferential rigidity of the tread part 16 is obtained by a circumferential belt layer 20B formed by arranging plural organic fiber cords practically in parallel with the tire equatorial surface CL so as to secure the inner pressure and obtain the excellent high speed durability. Since circumferential main grooves 24 are provided with projections 26 as a groove bottom damage preventing means at each bottom part, even if a foreign material is caught in the circumferential main grooves 24 when traveling on a bad road, damage of the groove bottom can be prevented. |
