EP2323858

Particular embodiments of the present invention include a multi-stage tire tread having a plurality of wear layers, each said layer being located at a different depth of the tire tread, the tread including one or more tread elements including a contact surface and having a first wear layer and a second wear layer, wherein the second wear layer is located below the first wear layer. The tire tread also includes a longitudinal groove extending in a longitudinal direction within the second wear layer of the tread element, wherein said longitudinal groove becomes exposed after a depth of the first wear layer has been worn. The tire tread further includes one or more lateral grooves extending from the longitudinal groove in a lateral direction within the second wear layer of the tread element. The invention also provides a mold element for forming portions of the multi-stage tread.

From the international application WO2010030276