Patent ID: 6321180
Filing Date: 2001-11-20
Classification: B60C

Abstract:
A method for characterizing the potential noise level generated during the rotation of a tire from a tire tread contacting a road surface, comprising the steps of:a) determining the location of a leading edge of a footprint of said tire tread which first comes into contact with said road surface when said tire normally loaded and normally inflated rotates with respect to said location of a trailing edge which is the opposite edge of said footprint that last comes into contact with said road surface when said tire rotates;b) determining the length (L) of said footprint from said leading edge to said trailing edge extending along a centerline (CL) through said footprint, said centerline being disposed halfway between a first lateral edge and a second lateral edge of said footprint of said tire tread;c) determining the length (A.sub.1) of said footprint from said leading edge to said trailing edge in proximity to said first lateral edge of said footprint at a location corresponding to about 80% of the distance (W.sub.1), W.sub.1 being the lateral distance from said centerline CL to said first lateral edge;d) determining the length (A.sub.2) of said footprint from said leading edge to said trailing edge in proximity to said second lateral edge of said footprint at a location corresponding to about 80% of the distance (W.sub.2), W.sub.2 being said lateral distance from said centerline CL to said second lateral edge;e) calculating the footprint shape factor (FSF80%) of said tire with an equation ##EQU5##when said aspect ratio of said tire is above about 60; andf) measuring said noise level of said tire when 0.9<FSF80%<1.6.