Patent ID: 8794285

Claim:
A pneumatic tire for motorcycles having a tread portion formed in a circular shape, said tread portion having a crown portion which has a spiral belt layer ( 3 ) in its inside in the radial direction of the tire, said spiral belt layer having an angle of 0 to 5° with respect to the equatorial direction of the tire and an arrangement width 0.5 to 0.8 times as large as the tread width, wherein said spiral belt layer is arranged in such a manner that the center of the transverse direction of said spiral belt layer coincides with the tire equator and the curvature radius (R 1 ) from the end portion of said spiral belt layer to the end portion of the tread portion is larger than the curvature radius (R 2 ) from the end portion of said spiral belt layer to the tire equatorial plane, and further comprising a belt reinforcement layer ( 6 ) positioned radially outside of said spiral belt layer ( 3 ) and extending in the transverse direction beyond both end portions of said spiral belt layer ( 3 ), wherein a shoulder portion reinforcement belt layer is arranged adjacent to said spiral belt layer in an arrangement width of 0.5 to 2.0 W, where W is a width of the portion having no spiral belt layer in said tread portion, the shoulder portion reinforcement belt layer exists only outside of said spiral belt layer in the transverse widthwise direction, and said shoulder portion reinforcement layer has an angle of 10° or more and 90° or less with respect to the equatorial direction of the tire.