Patent ID: 7422043

Claim:
A pneumatic tire having a tread surface comprising: main grooves extending in a circumferential direction of the tire and across the direction; sub-grooves extending in the circumferential direction of the tire and optionally across the direction to connect with the main grooves, said sub-grooves having a depth which is shorter than that of the main grooves; and blocks separated and defined by the main grooves and the sub-grooves, wherein each sub-groove extending in the circumferential direction and separated by the main grooves has a bottom with two ends in the circumferential direction, on which bottom (i) two first raised portions are formed in the vicinity of the respective two ends of the bottom, and (ii) at least one second raised portion formed between the two first raised portions, wherein the at least one second raised portion is only one second raised portion, and L 1 /L is in a range of 0.2 to 0.8, where L is a distance between the two first raised portions and L 1 is a distance between a center of the second raised portion and one of the two first raised portions, wherein the distance L 1 is different from a distance L 2 which is a distance between the other of the two first raised portions and the center of the second raised bottom portion.