| 摘要 |
PURPOSE:To prevent various partial abrasion of a tread, by setting the width of a main groove in a specific ratio to the width of the tread, and further by dividing a shoulder rib into a plurality of small ribs in a specific position by an auxiliary groove having a specific width and depth. CONSTITUTION:A tread 1 is divided into two shoulder ribs 3 and at least one center rib 4 by at least two main grooves 2 extending in the circumferential direction of a tire. In this case, the main groove 2 is formed to have a wide width, and the width W2 of the groove is set to be 4 to 8% of the width T in the ground contacting region of the tread 1. Further, each shoulder rib 3 is divided into a plurality of small ribs 6 and 7 by at least one auxiliary groove 5 extending zigzag in the circumferential direction of the tire. And with regard to the auxiliary groove 5, the ratio of the distance B from the tread end 10 to itself to the width A of the shoulder rib 3 is set to be 50% or less; the ratio of the width W5 to the tread width T to be 3% or less; and the ratio of the depth to the depth of main groove 2 to be 30% or more, respectively. |
