| 摘要 |
PURPOSE:To improve wear resistance and comfortability in the title tire having a lug pattern, by forming a lug by a rectangular portion and an elongate portion, and arranging the rectangular portionin a central area of a tread surface while arranging the elongate portion in both side areas thereof in such a manner that a negative ratio between the central area and the both side areas is set to a predetermined value. CONSTITUTION:A treated portion 10 is substantially uniformly partitioned into a central area 11 and both side areas 12 and 13. substantially rectangular portions 16 and 17 of lugs 14 and 15 are arranged in the central area 11, and a zigzag main groove 29 is formed by central ridge lines 21-24 of the rectangular portions 16 and 17. Overall ridge lines 25 and 26 of the lugs 14 and 15 are equally spaced from ridge lines 27 and 28 of elongate portions 18 and 19 of the lugs, respectively, to form a continuous curve. An angle between the ridge lines 25 and 26 in the direction of a tire width is gradually decreased toward the center of the tread portion, and a negative ratio between the central area and the both side areas is set to abut 70% or less. With this arrangement, wear resistance and comfortability are improved. |
