Patent ID: 9731559
Date: 2017-08-15
CPC Classifications: B60C

Claim:
1. A pneumatic motorcycle tire which comprises a tread portion, and side wall portions and bead portions extending from both sides of the tread portion, and whose rotation direction when the tire is mounted on a vehicle is designated, wherein the tire tread comprises a branched main groove composed of a first groove extending inclined toward the designated tire rotation direction on one side in the tire width direction, a second groove extending from an end portion of the first groove in the reverse rotation direction of the designated tire rotation direction inclined toward the designated tire rotation direction on the other side in the tire width direction, and a third groove extending from an end portion of the first groove and second groove in the reverse rotation direction of the designated tire rotation direction toward the reverse rotation direction of the designated tire rotation direction, wherein a connecting portion of the first groove and the second groove is formed in a curved shape, the first groove is formed in a curved line having the center of the radius of curvature on the side of the reverse rotation direction of the designated tire rotation direction, the second groove is formed in a curved line having the center of the radius of curvature on the side of the reverse rotation direction of the designated tire rotation direction, and the third groove is formed in a curved line having the center of the radius of curvature on the side of the tire center portion; wherein the connecting portion of the first groove and the third groove, and the connecting portion of the third groove and the second groove are further formed in a curved shape; wherein, letting the radius of curvature of the connecting portion of the first groove and the second groove be R