Low profile pneumatic radial tires

Abstract

A low profile pneumatic radial tire comprises at least one carcass ply containing cords arranged substantially at 90.degree. relative to a circumference of a tread, and a belt consisting of at least two belt layers which are composed of metal cords inclined relative to the circumference of the tread and intersected with one another between the adjacent belt layers and which are arranged upon a crown of the carcass. The tread surrounds the crown, and is provided with a pair of circumferential main grooves which are disposed symmetrically with respect to an equatorial plane of the tire and which divide a treading portion of the tread into a central region and axially opposite side regions and which are separated by a distance ranging from 45 to 65% of a maximum width of the tire in the state that the tire is assembled onto a normal rim and inflated at a normal internal pressure. The width of the belt ranges from 110 to 130% of a distance between intersections of an imaginary straight line which tangentially contracts with a top surface of a wear indicator projecting from a bottom of each of the circumferential grooves and which is drawn in parallel with a tire rotary axis and a tire contour line at axially opposite side regions of the tread, and the thickness of a tread rubber at maximum width edges of the tread ranges from 30 to 80% of that at the intersections.