Abstract: The present invention provides a belt formed of a spirally wound strip member constituted of a few juxtaposed cords and rubber coating thereon, with a structure which can absorb influence of difference in winding diameter at the unit width portion of the strip member without deteriorating productivity of the tire.

Abstract: In the pneumatic radial tire of the present invention, a total strength K0 of a belt layer 20 in a circumferential direction of the tire per unit of width at a tire equator surface position P0 is set greater than a total strength of the belt layer 20 in the circumferential direction of the tire per unit of width at a width position P2 corresponding to ? of a maximum width of the belt layer having the tire equator surface CL as a center.

Abstract: The present invention provides a belt formed of a spirally wound strip member constituted of a few juxtaposed cords and rubber coating thereon, with a structure which can absorb influence of difference in winding diameter at the unit width portion of the strip member without deteriorating productivity of the tire.

Abstract: A pneumatic radial tire for an airplane comprises a pair of bead cores, a carcass comprised of at least one carcass ply, a main belt comprised of at least two belt layers, an auxiliary belt comprised of plural layers, and a tread, wherein the main belt has a lamination thickness satisfying 0.2?G1/G0?0.8 as a relation between a lamination thickness at the widthwise center of the tire (G0) and a lamination thickness at a position corresponding to ? of a maximum width (G1), and the tread satisfies 0.85?DS/DC?1.1 as a relation between a tread thickness at a widthwise center position of the tire (DC) and a tread thickness at a position of a width corresponding to 80% of a maximum width of the main belt (DS), and has a radius of curvature on an outer surface of the tread formed by filling a normal internal pressure satisfying 0.4?R2/R1?3.

Abstract: In the pneumatic radial tire of the present invention, a total strength K0 of a belt layer 20 in a circumferential direction of the tire per unit of width at a tire equator surface position P0 is set greater than a total strength of the belt layer 20 in the circumferential direction of the tire per unit of width at a width position P2 corresponding to ? of a maximum width of the belt layer having the tire equator surface CL as a center. In this way, it is possible to suppress the quantity consume of material in the belt layer 20, and to suppress the amount of expansion of tread rubber in a tread central region in the circumferential direction thereof when a standard internal pressure is charged and when the tire is rotated at high speed, thereby suppressing the growth of tire diameter. Since the expansion amount of the tread rubber in the circumferential direction is suppressed, the tension of the rubber is reduced.