Patent ID: 7438101

Claim:
A pneumatic tire in which blocks, which are partitioned through circumferential main grooves extending in a circumferential direction of the tire and lateral main grooves in directions orthogonal thereto, are disposed at intervals at a tread portion, wherein said circumferential main grooves include inner circumferential main grooves that are disposed on each side of a tire equator and outer circumferential main grooves that are disposed outside thereof, a portion between said inner circumferential main grooves is formed into a rib continuously extending in the circumferential direction of the tire, a portion between said inner circumferential main groove and said outer circumferential main groove is formed into an inner row of blocks aligned in the circumferential direction of the tire, and a portion between said outer circumferential main groove and a tread end is formed into an outer row of blocks aligned in the circumferential direction of the tire, only the blocks of said inner row are formed as concave blocks each having a stepped concave portion, said stepped concave portion extending not along a block side edge located outside in the tire axial direction but along a block side edge located inside in the tire axial direction, wherein the concave portion has a depth ha from a block top surface that corresponds to 20 to 70% of a block height H 0 of the concave blocks, a length La of the concave portion in the tire circumferential direction that corresponds to 50 to 95% of a circumferential length L 0 of the block side edge, and a width Wa of the concave portion in the tire axial direction of 5 to 20 mm, and a bottom surface of the concave portion is in parallel with the block top surface.