| 摘要 |
<p>A tread (2) for a pneumatic tire (1) has a central portion defining two circumferentially extending center ribs (22, 23) having an axial width RW, and RN2 ranging from 5 % to 25 % of the tread width TW. The centermost circumferentially extending groove (8) has on both sides a tapered groove wall edges which form with a plane parallel to the equational plane acute angle α1 and α2 ranging between 1 and 10°. The tread height near both edges of the centermost groove extend radially above the average tread height a maximum extra tread height of between .3 mm and 1.7 mm. The extra tread height diminishes progressively from the groove edges P0P1 towards the respective shoulder (3, 4) a distance not exceeding 10 % of the tread width.</p> |
