Pneumatic radial tire for motorcycle

A pneumatic radial tire for a motorcycle, the tire having a pair of bead sections, a pair of side wall sections, provided consecutively with the bead sections, and a tread section, provided consecutively in a toroid form between both of the side wall sections, the tire further having at least one layer of carcass and a belt layer, the at least one layer of carcass reinforcing each section between the bead sections, the belt layer being disposed at a tire radial outer side of the carcass and having a reinforcement cord spirally wound in a peripheral direction,

• wherein the tread section is formed of a center section rubber and both side rubber, the center section rubber being disposed in a widthwise center region of the tire and on both sides of a tire equator, the both side rubber being disposed on both widthwise ends of the tire;
• wherein the tread section has a structure in which the center section rubber and the both side rubber are successively laminated upon each other at the both widthwise ends of the tire;
• wherein a ratio of a thickness of the both side rubber in the tread section increases towards the both widthwise ends of the tire;
• and wherein a modulus of the both side rubber is lower than a modulus of the center section rubber.