A motorcycle tyre for traveling on rough terrain, the tyre includes a tread portion provided with blocks. The at least one of the blocks includes a ground contact surface having a pair of lateral edges extending in a tyre axial direction. The at least one of the blocks is provided with a pair of lateral narrow grooves extending in the tyre axial direction on the ground contact surface to form a pair of edge-side portions defined between the pair of lateral narrow grooves and the pair of lateral edges. The at least one of the pair of edge-side portions includes a neck portion having a minimum circumferential length thereof, wherein a circumferential length of the at least one of the pair of edge-side portions increases toward axially both sides from the neck portion.

An aerodynamically optimized drag-reduction means and method for optimal minimization of the drag-induced resistive forces upon a terrestrial vehicle wheel, where the drag-induced resistive moments on wheel surfaces pivoting about the point of ground contact are reduced, and the vehicle propulsive forces needed to countervail the resistive forces on the wheel are reduced. The drag reduction means includes: a streamlined wheel cover positioned on a vehicle to shield the faster moving upper wheel surfaces from headwinds; a streamlined wind-deflecting fairing positioned on a vehicle to shield the faster moving upper wheel surfaces from headwinds; an engine exhaust pipe disposed on a vehicle whereby exhaust gases deflect headwinds to shield the faster moving upper wheel surfaces of an automotive wheel; an automotive spoked wheel having streamlined oval-shaped wheel spokes arranged in one or more rows for greater axial strength; a streamlined tailfin rotatably attached to a wheel spoke, which thereby may pivot about the spoke in response to varying crosswinds; and a tire having streamlined tread blocks arranged in an aerodynamic pattern.

A motorcycle pneumatic tire, in which the tread includes a central rubber and a side rubber, having a lower modulus than the central rubber, that are sequentially laminated in both tire widthwise side portions, the side rubber extending to a tire width-direction inner side further than a point at ¼ of a tread width on a tire width-direction outer side from a tire equator. A tire ground-contact surface has a tread pattern that includes plural inclined grooves and, when the tread width is equally divided in eight, a region constituting a range of ¼ to ⅜ of the tread width on the tire width-direction outer side from the tire equator has the largest number of inclined grooves included per a single pitch of the tread pattern, and the depth of the inclined grooves is greater than the thickness of the side rubber in at least a part of the region.

Provided is a motorcycle pneumatic tire in which the wet grip performance is improved while the steering stability during turning is ensured. The motorcycle pneumatic tire includes, on its ground-contact surface: a first inclined groove (21) that extends on a tire width-direction outer side from the vicinity of a tire equator and is inclined in the same direction as a tire rotation direction; and a short groove (22) that is arranged on the extension of a tire width-direction outer end of the first inclined groove (21). The tire width-direction outer end of the first inclined groove is positioned in the vicinity of a point at ¼ of a tread width (TW) from the tire equator on the tire width-direction outer side, while a tire width-direction inner end of the short groove is positioned in a range of ¼ to 5/16 of the tread width (TW) from the tire equator on the tire width-direction outer side; an inclination angle of the first inclined groove with respect to a tire circumferential direction increases toward the tire width-direction outer side; and an angle θ.sub.A formed by a groove wall of the tire width-direction outer end of the first inclined groove with respect to the direction perpendicular to the tire surface, and an angle θ.sub.B formed by a groove wall of the tire width-direction inner end of the short groove with respect to the direction perpendicular to the tire surface, satisfy a relationship of θ.sub.A>θ.sub.B.

A motorcycle tire comprises a pair of bead portions each with a bead core therein and a bead bottom surface. In a non-rim assembled state in which the bead portions are held such that the axial distance between the axially outer surfaces of the bead portions matches the rim width of a regular rim, a conditional expression: 0.99 =< Dc/(Dr+2T) =< 1.00, is satisfied, wherein “Dc” is the inner diameter of the bead core at the axial center position of the bead core, “Dr” is the rim diameter of the regular rim, and “T” is the radial distance from the inner surface of the bead core to the bead bottom surface at the axial center position.

Provided is a motorcycle tire 2 that can enhance a stiffness feeling while suppressing deterioration of a ground-contact feeling. A bead portion TB of the tire 2 includes a core 18. An outer surface of the bead portion TB includes a seat surface 24, a flange surface 26, and a heel surface 28. An inner diameter dw of the core 18, a rim diameter D, an inner diameter dA of the tire 2 at a heel reference point PH, and an inner diameter dB of the tire 2 at the seat reference point PS satisfy the following formulas.

dw/D≥1.0041

dA/D≤0.9966

dA−1.72≤dB≤dA−0.73

A pneumatic tire has a tread reinforcing layer comprising a net structure formed from a tape of rubber coated reinforcing cord(s). The net structure comprises first oblique segments and second oblique segments of the tape which intersect with each other, forming interspaces therebetween. The first oblique segment has a first axial outer part in which the angle of the tape with respect to the tire circumferential direction decreases toward one end in the tire axial direction of the net structure. The second oblique segment has a second axial outer part in which the angle of the tape with respect to the tire circumferential direction decreases toward the above-said one end of the net structure. The first axial outside part is connected to the second axial outside part directly or through a circumferential segment of the tape.

A motorcycle tire includes a tread portion, a pair of sidewall portions, a pair of bead portions, a toroidal carcass extending between the pair of bead portions, and a belt layer and a band layer disposed outwardly in the tire radial direction of the carcass in the tread portion. The carcass includes a plurality of carcass cords. The band layer includes a jointless band ply having a band cord wound spirally at an angle equal to or less than 5 degrees with respect to a tire circumferential direction. The belt layer includes a plurality of belt cords arranged in a direction intersecting with the carcass cords. The belt cords intersect with the carcass cords at an intersection angle θc in a tread crown region, and intersect with the carcass cords at an intersection angle θs in tread shoulder regions, and the intersection angle θc is greater than the intersection angle θs.

A tread portion 2 of a tire 1 includes a plurality of shoulder blocks 11 and a plurality of middle blocks 12. An inner edge 11B in the tire axial direction of a tread surface of each shoulder block 11 protrudes on an outer side in a tire radial direction with respect to a virtual profile 18. A side surface S on the inner side in the tire axial direction of each shoulder block 11 includes one first side surface S1 extending from the inner edge 11B toward a groove bottom, and at least one second side surface S2 extending from a bottom side end of the first side surface S1 toward the groove bottom, and the second side surface S2 is a surface inclined toward the inner side in the tire axial direction relative to the first side surface S1.

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.