PNEUMATIC RADIAL TIRE

PURPOSE:To reduce interior road noise without deteriorating other performance. CONSTITUTION:On the width directional outside of the first belt 20A, a reinforcing layer 24 consisting of unextensible cord is arranged, and the outside end of the reinforcing layer 24 is substantially matched with the end part of the second belt 20B. The width BW1 of the first belt 20A is 80% of the tread width SW or less. As the reinforcing layer 24 is positioned in the tire radius directional inside of the second belt layer 20B and serves as a tension side when the tire runs over a road rough part, bending rigidity of a tread 22 around the both end parts of the tire tread width is improved further in comparison with the intermediate part. A ratio of deformation in the tire side part adjoining the width directional both end parts in the tread 22 according to the road surface shape in the travel on the rough road surface is reduced, so that interior road noise is reduced. As softening of tread rubber, softening of rigidity of a tire case, and the like are not needed, other performances such as abrasion resistance and operation stability are not deteriorated.