Patent ID: 8944124
Filing Date: 2015-02-03
Classification: B60C,Y10T

Abstract:
1. A pneumatic tire for a motorcycle comprising a tread portion comprising a tread rubber having a layered structure of one or more layers, a pair of side wall portions continuously extending from each side of the tread portion inward in a radial direction of the tire and bead portions each continuing into a radially inner side of each of the side wall portions, wherein a ground contact region of the tread portion comprises five regions of: a central region including a tire equatorial plane; a pair of shoulder regions each including a tread ground contact end; and a pair of intermediate regions each located between the central region and each of the shoulder regions, loss tangent of at least a portion forming a ground contact surface of an intermediate tread rubber disposed over an entire region of the intermediate regions is larger than both of loss tangent of at least a portion forming a ground contact surface of a central tread rubber disposed over an entire region of the central region and loss tangent of at least a portion forming a ground contact surface of a shoulder tread rubber disposed over an entire region of the shoulder regions, an intersection angle β, in a tire equatorial plane side, formed by an approximate straight line of a join line of the intermediate tread rubber and the shoulder tread rubber and a tangent line at a join point of the intermediate tread rubber and the shoulder tread rubber in a ground contact surface is smaller than an intersection angle α, in a tire equatorial plane side, formed by an approximate straight line of a join line of the central tread rubber and the intermediate tread rubber and a tangent line at a join point of the central tread rubber and the intermediate tread rubber in a ground contact surface, and the join lines between the respective regions are the only join lines.