Patent ID: 7395845
Filing Date: 2008-07-08
Classification: B60C,Y10T

Abstract:
1. A pneumatic radial tire comprising a belt layer disposed inside a tread portion and outside a carcass in a radial direction of the tire, and a band layer consisting of a pair of edge bands disposed radially outward of the belt layer and at opposite edge portions of the belt layer, wherein when a cross sectional area of one band cord is defined as S (unit; mm 2 ) and a modulus of the band cord when its elongation is 2% is defined as M (unit; N/mm 2 ) and the disposition density of the band cord per 1 cm of the band layer edge bands, is defined as D (unit; the number of band cords/cm), an elongation resistance value K (unit; N·the number of band cords/cm) of the edge bands, which is determined by the following equation (1) is set to greater than 700 and 830 or lower: and elongation percentage T(%) of the edge band cord in the tire in its natural state in which the tire is not assembled to a rim is set to 0.75% or higher and 1.2% or lower.