A motorcycle tire pair includes a front tire 2 and a rear tire 42. A center arc index Ac, a middle arc index Am, and a shoulder arc index As are obtained on the basis of a contour line TLf of a tread surface 16 of the front tire 2 and a contour line TLr of a tread surface 56 of the rear tire 42. In the tire pair, the middle arc index Am is larger than the center arc index Ac, and the shoulder arc index As is larger than the middle arc index Am.

The pneumatic tire includes a carcass layer, a belt layer disposed on an outer side of the carcass layer in a radial direction, and a tread rubber disposed on an outer side of the belt layer in the radial direction. Additionally, the carcass layer has a cord angle of 80° or more and 100° or less. Additionally, the belt layer is formed by layering a first reinforcing belt, a second reinforcing belt that is narrower than the first reinforcing belt, and an auxiliary belt that is spaced apart from a tire equatorial plane and disposed between the carcass layer and the first reinforcing belt. Additionally, the first reinforcing belt has a cord angle of 11° or more and 30° or less, the second reinforcing belt has a cord angle of 1° or more and 11° or less, and the auxiliary belt has a cord angle of 55° or more and 70° or less.

Provided is a pneumatic tire capable of providing improved steering stability performance on dry road surfaces and improved steering stability performance on wet road surfaces in a compatible manner. A chamfered portion (12A, 12B) and a non-chamfered portion (13A, 13B) are provided in each of an edge (11A) on a leading side and an edge (11B) on a trailing side of a sipe (11). In a meridian cross-sectional view, a profile line (PL1) of a rib (10) projects further to an outer side in a tire radial direction than a reference tread profile line (PL0). A radius of curvature TR (mm) of the reference tread profile line (PL0) and a radius of curvature RR (mm) of the profile line (PL1) satisfy a relationship of TR>RR. Only one of the chamfered portions (12A, 12B) on the leading side and the trailing side is disposed so as to straddle a maximum projection position (P). A maximum projection amount D (mm) of the rib (10) with respect to the reference tread profile line (PL0) and a maximum width (W) (mm) of the chamfered portion (12A, 12B) satisfy a relationship of 0.05 mm.sup.2<W×D<1.50 mm.sup.2.

A tire comprises a tread portion provided with a first circumferential groove and a second circumferential groove which are disposed on one side and the other side, respectively, of a cambered-tire tread center line. The cambered-tire tread center line is defied by a line extending in the tire circumferential direction, along which a circumferential length of the ground contacting patch of the tire becomes maximum when the tire mounted on a normal rim and inflated to a normal pressure, is placed on a flat horizontal surface at a non-zero camber angle, and loaded with a normal tire load in the vertical direction.

A tire comprises a tread portion provided with two circumferential grooves disposed one each side of the tire equator and extending continuously in the tire circumferential direction, and a shoulder land region defined on the axially outside of each of the two circumferential grooves. The shoulder land region is provided with oblique grooves inclined with respect to the tire axial direction. The oblique grooves include first oblique grooves having axially inner ends, and second oblique grooves having axially inner ends positioned axially outside the axially inner ends of the first oblique grooves.

A tire has a tread portion divided into a crown land region, shoulder land regions, and middle land regions. The crown land region comprises a crown axial central portion. The middle land region comprises a middle axial inner portion and a middle axial outer portion. The shoulder land region comprises a shoulder axial inner portion and a shoulder axial central portion. The radius Rmi of curvature of the middle axial inner portion is 0.80 to 1.20 times the radius Rcc of curvature of the crown axial central portion. The radius Rsc of curvature of shoulder axial central portion is 0.80 to 1.20 times the radius Rmo of curvature of middle axial outer portion. The radii Rsc and Rmo are less than the radii Rcc and Rmi. The radius Rsi of the shoulder axial inner portion is less than the radii Rsc and Rmo.

A motorcycle tire pair includes a front tire 2 and a rear tire 42. A center arc index Ac, a middle arc index Am, and a shoulder arc index As are obtained based on a contour line TLf of a tread surface 16 of the front tire 2 and a contour line TLr of a tread surface 56 of the rear tire 42. In the tire pair, the middle arc index Am is greater than or equal to the center arc index Ac, and the shoulder arc index As is smaller than the center arc index Ac.

In a tire 12, a tread 14 includes a tread main body 44 and edge portions 46. A wear resistance index of each edge portion 46 obtained according to JIS K6264-2 is higher than that of the tread main body 44. An outer surface S of the tire 12 includes a tread surface ST, a pair of shoulder surfaces SH connected to the tread surface ST, and a pair of side surfaces SW connected to the shoulder surfaces SH. Each shoulder surface SH includes an outer surface formed by the edge portion 46, and a contour of each shoulder surface SH is represented by a circular arc having a center at an inner side.

An outer surface of a tire can include a tread surface and a pair of side surfaces. A contour line of the tread surface can include a center arc, a pair of middle arcs, a pair of side arcs, and a pair of shoulder arcs. A contour line of each side surface can be connected to the shoulder arc. A position, on the outer surface, corresponding to a ground-contact end obtained by applying a load that is 80% of a standardized load, to the tire in a standardized state, and bringing the tire into contact with a flat surface is a reference ground-contact position, and a boundary between the shoulder arc and the side arc is a reference boundary. The reference boundary can be located axially outward of the reference ground-contact position. A ratio of a distance in an axial direction from an equator plane to the reference boundary to a distance in the axial direction from the equator plane to a tread reference end TE can be not less than 0.94 and not greater than 0.98.

Provided is a pneumatic tire having at least one carcass layer as a skeleton extending in toroidal shape over a pair of bead portions, at least one belt layer and a tread disposed on an outer side in the radial direction of a crown portion of the carcass. In a tire section in the widthwise direction in state where the tire is assembled to an application rim, ratio BD/BW of radius difference BD between radius at a center portion and radius at an end portion in the widthwise direction of an innermost layer of the belt layer, to width BW of the innermost layer, ranges from 0.01 to 0.04, and ratio TD/TW of radius difference TD between radius at a center portion and radius at an end portion of the tread in the widthwise direction of a tread ground surface, to tread ground-contact width TW, satisfies BD/BW<TD/TW.