Abstract: A pneumatic tire according to the present invention includes a tread surface having a tire rotation direction designated in one direction. The tread surface has a straight main groove extending in a circumferential direction of the tire in the center, and lateral grooves obliquely extending in a width direction of the tire on both sides thereof, defining blocks thereon. On both sides of the straight main groove, left and right slant main grooves are arranged to cross three or more lateral grooves. Both ends of-the slant main grooves are positioned within the blocks, and the groove width thereof is gradually enlarged from both end portions toward the center portion of the slant main groove. The inclination angle of the slant main grooves relative to the tire circumferential direction is set in a range of 10 to 45°, and the maximum groove width thereof is set to 80 to 110% of the groove width of the straight main groove.

Abstract: A pneumatic tire comprising a rubber member containing a short fiber (A′) formed by the fibrillation of a short fiber (A) whose cross section takes a sea-island structure essentially composed of at least two polymers.

Abstract: A pneumatic tire comprising a rubber member containing a short fiber (A′) formed by the fibrillation of a short fiber (A) whose cross section takes a sea-island structure essentially composed of at least two polymers.

Abstract: A pneumatic tire comprising a rubber member containing a short fiber (A′) formed by the fibrillation of a short fiber (A) whose cross section takes a sea-island structure essentially composed of at least two polymers.

Abstract: A pneumatic tire according to the present invention includes a tread surface having a tire rotation direction designated in one direction. The tread surface has a straight main groove extending in a circumferential direction of the tire in the center, and lateral grooves obliquely extending in a width direction of the tire on both sides thereof, defining blocks thereon. On both sides of the straight main groove, left and right slant main grooves are arranged to cross three or more lateral grooves. Both ends of-the slant main grooves are positioned within the blocks, and the groove width thereof is gradually enlarged from both end portions toward the center portion of the slant main groove. The inclination angle of the slant main grooves relative to the tire circumferential direction is set in a range of 10 to 45°, and the maximum groove width thereof is set to 80 to 110% of the groove width of the straight main groove.

Abstract: A pneumatic tire comprising a rubber member containing a short fiber (A′) formed by the fibrillation of a short fiber (A) whose cross section takes a sea-island structure essentially composed of at least two polymers.

Abstract: A pneumatic tire comprising a rubber member containing a short fiber (A′) formed by the fibrillation of a short fiber (A) whose cross section takes a sea-island structure essentially composed of at least two polymers.

Abstract: A pneumatic radial tire includes a belt layer, comprised of steel cords having a lateral flat cross-section, arranged around an outer periphery of a tread portion of a carcass layer so that the diameter direction of the steel cords is made to follow the planar direction of the belt layer, the steel cord is made a flat 1.times.6 twist structure comprised of filaments of a filament diameter d of 0.20 to 0.40 mm, the long diameter D.sub.L and twist pitch P of the steel cord taken out from the tire are made with respect to the filament diameter d as follows:3.67 d-0.04.ltoreq.D.sub.L .ltoreq.3.67 d+0.1630d.ltoreq.P.ltoreq.45dand the elongation of the steel cord caused when increasing a load from 0.25 kg to 5.0 kg is made 0.25% or less.