| 摘要 |
PURPOSE: To attain excellent ice traveling performance without reducing snow traveling performance by forming a slant groove by low and high slant grooves in the center area of a tread, and substantially circumferentially continuing a block just under a load by a slender groove provided on a part thereof which is closed just under the load. CONSTITUTION: Blocks 5, 6 having sipes 7 are formed by slant grooves 2, 3 in the center area TC of a tread partitioned by a circumferential groove 1, and the negative ratio is set to 20-30%. The slant grooves 3, 2 have inclinations of 40 deg. or more and less than 50 deg. to the circumferential direction, respectively, the relatively large block 5 has such a slender groove 4 less than about 1mm that it is closely adhered just under a load, the slender groove 4 is closed just under the load, whereby the blocks on both side parts are closely adhered and substantially continuously extended in the circumferential direction. Thus, the circumferential groove 1 ensures the grip force in the tire transverse direction, the slant grooves increase the transverse lateral grip force and have an edge effect on the vertical direction, and ice traveling performance can be improved with hardly reducing snow traveling performance. |
