Pneumatic tire with tread including protruding portions on wall surface of groove

A pneumatic tire , in which at least one rib groove extended in a tire circumferential direction is formed on a tread surface portion T of a tread portion , and portions discontinuous in terms of rigidity are formed in a circumferential direction of rib lines B formed by the rib groove , the discontinuous portions causing variations of tire axle force. Rigidity changing portions which cancel the variations of the tire axle force are provided in the rib groove , the variations being caused by the discontinuous portions . Thus, vibrational force to an axle is lowered, and pattern noise caused thereby is reduced effectively.