Patent ID: 9242511
Filing Date: 2016-01-26
CPC Classification: B60C

Claim Text:
1. A pneumatic tire comprising a tread portion, the tread portion provided with: a pair of circumferentially extending crown main grooves arranged on both sides of a tire equator; a pair of circumferentially extending shoulder main grooves arranged axially outside the crown main grooves; a crown rib between the crown main grooves; a pair of middle ribs each between the crown main groove and the shoulder main groove; and a pair of shoulder ribs each between the shoulder main groove and a tread edge, wherein each of the shoulder rib is provided with a plurality of shoulder lateral grooves spaced at a tire circumferential pitch Ps and a shoulder narrow groove, each of the shoulder lateral grooves extends axially inwardly from the axially outside of the tread edge at an angle α of from 65 to 115 degrees with respect to a tire circumferential direction, each shoulder lateral groove has an axial inner end terminated within the shoulder rib, the shoulder narrow groove extends circumferentially through the axial inner ends of the shoulder lateral grooves and has a groove width being smaller than a groove width of the shoulder main groove, each of the middle rib is provided with a plurality of middle inclined grooves spaced at a tire circumferential pitch Pm, each of the middle inclined grooves extends axially inwardly from the shoulder main groove at an angle β of from 0 to 75 degrees with respect to the tire circumferential direction and has an axial inner end terminated within the middle rib, the crown rib is provided with a plurality of crown lateral grooves which extend across the crown rib and are spaced at a tire circumferential pitch Pc, a circumferential length Lm of the middle inclined groove is in a range of from 70% to 125% of the tire circumferential pitch Pm of the middle inclined grooves, the tire circumferential pitch Pm of the middle inclined grooves is set in a range of from 2.5 to 4.0 times the tire circumferential pitch Ps of the shoulder lateral grooves, and the tire circumferential pitch Pc of the crown lateral grooves is larger than the tire circumferential pitch Ps of the shoulder lateral grooves and smaller than the tire circumferential pitch Pm of the middle inclined grooves.