| 摘要 |
PURPOSE:To reduce the generation of noise by setting a size of each part of a tread, surface area of a lug forming groove and its size or the like respectively to the specific relation, in the case of a tire which provides a large number of lug forming grooves to be arranged tilting in the same direction in the tread. CONSTITUTION:A tread face 3 in the surface of a tread part 1 arranges a large number of grooves 4 with a predetermined space in the peripheral direction of a tire respectively in both right and left side parts, and many lugs 5 are formed between these grooves 4. Here a tread radius R2, forming a shoulder part 3s, is set to 40-60% the tread radius R1 forming a center part 3c. While width (w) of a region, occupied by the tread radius R2, is set to 30-40% the 1/2 developed width W of a tread. Further each groove 4 sets its total surface area to 16-22% the total surface area of the tread. Length l of each groove 4 in a width direction of the tread is set to 72-76% the 1/2 developed width W of the tread. |
