TIRE TREAD HAVING A PLURALITY OF WEAR LAYERS

摘要

Particular embodiments of the present invention include a multi-stage tire tread having two or more wear layers comprising an outer wear layer and one or more inner wear layers arranged within the thickness of the tread below the outer wear layer. One or more outer grooves are arranged within the outer wear layer, while one or more inner grooves arranged within at least one of the one or more inner wear layers. The tread further includes a volumetric void ratio equal to approximately 0.25 to 0.40 in the unworn condition and approximately 0.25 to 0.40 in a worn condition where the outer, ground-engaging side is arranged along one of the inner wear layers in the worn condition, the tread further having a contact surface ratio equal to approximately 0.66 - 0.72 in the unworn condition and approximately 0.56 - 0.66 in the worn condition.