PURPOSE: To increase the degree of biting into an unlevelled road and obtain strong traction, by providing a tread with numerous blocks which are separately located on the peripheral surface of the tread and have recesses which are opened on their front sides as to the rotating direction of a tire.

CONSTITUTION: A tire 11 appropriate to a motorcycle such as a motor crosser comprises a tread 12 and numerous blocks 13 which separately project on the peripheral part of the tread and are shaped as a rectangular parallelepiped or the like. Each block 13 has a recess 14 opened on its front side as to a rotating direction shown by an arrow in Fig. A rib 15 is provided in the center of the recess 14 and extens in the circumferential direction of the tire to reinforce the block. The edges of each block 13 are made sharp to increase rolling resistance on an unlevelled road 16 such as a sandy place.