SACRIFICIAL RIBS FOR IMPROVED TIRE WEAR

摘要

The present invention provides a tire with a sacrificial rib to protect the main ribs of the tire's tread by delaying the onset of irregular wear and the growth thereof. The improved tire tread comprises a plurality of main ribs formed by grooves extending generally circumferentially around an outer surface of the tire to form a main tread width for contacting the supporting surface. A sacrificial rib is provided for contacting the supporting surface at each lateral side of the main ribs. The sacrificial rib is separated from the main ribs by a narrow shoulder groove having a groove width not greater than about 1.5 millimeter. The sacrificial rib has a surface width in the range of about 2.5 percent to about 12 percent of said tread width. The sacrificial rib has a recess defined by a radial offset from a transverse or lateral profile of the main ribs. The offset has a value in the range of about 0.50 millimeter to about 2.0 millimeters when the tire is new. A shape factor is used for defining the shape of the sacrificial rib where the shape factor has a value between about 0.10 and 0.50.