Radial tires having improved irregular wear resistance

In a radial tire having improved irregular wear resistance, which are reinforced with a belt cord layer and a carcass cord layer, the improvement which comprises:

• having a crown radius CR (in mm.), a radius of curvature of the ground contact surface of the tread at the cross-section containing the rotation axis of the tire, which is given by the following formula:
• ##EQU5## wherein SW (in mm.) represents the tire width under no load and standard inflation pressures as defined by The Tire and Rim Association, Inc.;
• and
• using, for at least the ground contact area of the tread, a rubber composition consisting essentially of 100 parts by weight of a styrene-butadiene copolymer rubber having a viscosity average molecular weight of not less than 2.times.10.sup.5 or a blend rubber consisting of not less than 30 parts by weight of said copolymer rubber and at least one of natural rubber, polyisoprene rubber and polybutadiene rubber, 5-60 parts by weight of at least one of a liquid styrene-butadiene copolymer, a liquid polyisoprene and a liquid polybutadiene having a viscosity average molecular weight of 2.times.10.sup.3 -1.5.times.10.sup.5, and 40-90 parts by weight of carbon black.