| 摘要 |
<p>PURPOSE: To restrict wandering in running in a dent such as a track on a road surface, and improve straight advance stability by setting a zigzag oscillation width of a shoulder main groove adjacent to a shoulder land part to be smaller than that of other main grooves, and setting a negative ratio of both side zones of a tread to be large to the limit of a specific magnification for the side zones of the tread as a residual part to a center 1/2 zone of the tread. CONSTITUTION: A tread 1 comprises at least four main grooves 2 zigzag- extended in circumferential directions, and land parts 3 parted by the main grooves 2, and a shoulder land part 3s of the land parts 3 is formed of a part of comb-shaped rib parts 5 and lugs 6 parted by lug grooves 4... extended from a tread end E. A zigzag oscillation width of a shoulder main groove 2s adjacent to the shoulder land part 3s is set to be smaller than other main grooves 2c, and a negative ratio of both side zones Rs is set to be large to the limit of 2.4 times for the side zones Rs of the tread 1 as a residual part to a center 1/2 zone Rc.</p> |
