| 摘要 |
PURPOSE:To reduce a pattern noise, by making small and large blocks different in perimeter direction lengths 1 pitch, and arranging a plurality of pitches different in pitch lengths at a predetermined disposition, and forming a tread pattern. CONSTITUTION:Block rows 21-25 are formed by means of longitudinal grooves 1 and latitudinal grooves 3. This block row whose 1 pitch is made up of one small and one large block 4b, 4a different in tire perimeter direction lengths a, b, is constituted with at least 3 kinds of pitches A-C which are different in pitch lengths 2. And, pitches A-C are disposed in an order in which the ratio of the large block perimeter direction length against the small block within 1 pitch becomes larger and at the same time, the order of disposition is reversed at a shoulder side and at a center side. Also, the ratio of the minimum pitch length and the maximum pitch length is set within the range of 1.2-1.6. As a result, the lowering of a cornering power is prevented, and a pattern noise can be reduced. |
