| 摘要 |
TIRE TREADS The tire treads (11) comprise an uneven number of axially spaced straight grooves (400-404) which extend circumferentially about the tire (10), the center groove (402) having its centerline on the equatorial plane (EP), and a plurality of circumferentially spaced laterally extending grooves (430-435), the axially innermost grooves (431-434) forming with the equatorial plane an angle comprised between 30.degree. and 60.degree., the two axially outermost grooves (430, 435) forming with the equatorial plane an angle comprised between 60.degree. and 80.degree.. The circumferentially and laterally extending grooves define rows of land portions having the shape of a large parallelogram adjacent to a small parallelogram. The small parallelogram has one of his small sides in the continuation of one of the sides of the large parallelogram delimiting a circumferentially extending groove (400-404). The length of the small side of the small parallelogram is changed in order to modify the performance characteristics of the tire.
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