TREAD PATTERN

In a pneumatic tire a plurality of circumferential main grooves 1 define a plurality of rib lines 2a, 2b, 2c and a plurality of lug grooves 3a, 3b, 3c in the rib lines define a plurality of blocks, the angles of the lug grooves with respect to the tire circumferential direction being in geometric progression within a repeating unit comprising a plurality of blocks of a rib line the ratio of the maximum to the minimum such angle being from 1.1 to 1.4. The angles which the lug grooves in the rib lines near to the shoulders of the tire make with the circumferential direction are greater than those made by the lug grooves in the rib lines near to the center of the tire.