Pneumatic tire for high speed under heavy load

Abstract

A pneumatic tire for a high speed under a heavy load is disclosed. In order to effectively refrain a crown radius of curvature of the tire from decreasing due to a centrifugal force, the tire is constructed as follows. The tire comprises a case reinforcing layer composed of a plurality of carcass plies mainly formed of organic textile cords inclined at an angle of at most 45.degree. to the circumferential direction of the tire and a plurality of reinforcing fabrics whose material and inclined angle to the circumferential direction of the tire are substantially the same as those of the cords of the carcass ply and interposed between the carcass plies. The plurality of reinforcing fabrics extend from those positions which are distant apart from one of bead portions through a tire crown portion and terminating at those positions which are distant apart from the other bead portion. The number of the reinforcing fabrics is at least 20% of the total number of both the carcass plies and the reinforcing fabrics. The total number of the case reinforcing layers is divided into two halves and one of the two halves cross the other halves. The reinforcing fabrics are gradually changing in width within a range between 35% and 60% of the inner peripheral length of the tire and symmetrically arranged with respect to a crown center portion.