A tire is provided with multiple projection parts in a groove bottom of a groove portion. The projection parts extend from one side wall to the other side wall opposed to the one side wall, the side walls forming the groove portion. The projection parts are arranged at predetermined intervals in the groove portion. Lateral groove portions that extend from the groove portion to a buttress section, and have openings in the buttress section are formed. Air supply mechanisms that supply air to the lateral groove portions are formed.