Motorcycle wheel tyre (1), comprising a carcass structure (2), a belt structure (6) arranged in a radially outer position with respect to the carcass structure (2) and a tread band (8) arranged in a radially outer position with respect to the belt structure (6). The tread band (8) comprises, in an axially inner annular portion thereof, a pair of circumferential grooves (20) arranged on opposite sides with respect to an equatorial plane (X-X) of the tyre (1). The carcass structure (2) comprises at least one carcass ply (3) having opposite end edges (3a) associated with respective annular reinforcing structures (4) to form respective beads (15). Each bead (15) comprises at least one reinforcing element (18) made of an elastomeric material having a rigidity in a circumferential direction greater than the rigidity in a radial direction.

A pneumatic tire mountable on a 15° tapered specified rim includes a bead core, a carcass, a steel cord reinforcing layer, a bead rubber layer, an organic fiber reinforced layer, and a first reinforcing rubber layer. A distance from a second line segment to a third line segment is from 4 mm to 12 mm, a complex modulus of the first reinforcing rubber layer is from 6 MPa to 10 MPa, an elongation at break of the first reinforcing rubber layer is from 300% to 450%, and a difference between a first height and a second height is from 3 mm to 15 mm.

In a pneumatic tire, a bead filler is radially outward of a bead core, a carcass turned up end is radially inward of an outer side end of the bead filler, the turned up end is spaced from a carcass body, a reinforcement layer is laterally outward of the bead filler, a sidewall rubber extends from a sidewall to the bead, an inner rubber reinforcing layer is between the bead filler and the reinforcement layer and adjacent to the turned up end, a crack suppression layer is between the reinforcement layer and the sidewall rubber, the crack suppression layer extends 5 mm or more from where the crack suppression layer overlaps, the reinforcement layer contacts the carcass body radially outwardly of the bead filler, and a 100% modulus Kc.sub.M100 of the crack suppression layer is at least 1.5 times that of the sidewall rubber.

A pneumatic tire mountable on a 15° tapered specified rim, the pneumatic tire including a bead portion, bead core, a carcass, a steel cord reinforcing layer, and a bead rubber layer. A distance from a second line segment to a third line segment is from 4 mm to 8 mm, and a ratio R2/R1 is from 0.935 to 0.975, wherein R2 is a tire radius at a bead toe of a bead base portion and R1 is a tire radius at a bead heel.

A pneumatic tire includes a bead portions and a bead core at the bead portions, the tire being mounted to a 15°-tapered specified rim. The bead portions include a portion inward in a radial direction of an extension line of an inner circumferential surface of the bead core, the extension line extending in the lateral direction, that is positioned outward in the tire lateral direction of an imaginary line passing through a first intersection point between the extension line and a tire inner surface and extends inward in the tire radial direction from the extension line at an angle perpendicular to the extension line. An angle α formed by the imaginary line and a line segment passing through a second intersection point between a bead base and the tire inner surface and the first intersection point between the extension line and the tire inner surface is from 0° to 25°.

A heavy-duty pneumatic tire includes a carcass ply including a main portion extending between bead cores and a pair of turn-up portions, a first reinforcing layer of a steel cord disposed in each bead portion in a U-shaped manner, and a second reinforcing layer of an organic fiber cord disposed in each bead portion and at least a part of the second reinforcing layer extending in a radial direction of the tire at an axially outward location of the first reinforcing layer. The second reinforcing layer includes an axially inner second ply and an outer second ply. The outer second ply has an inner end positioned below the bead core. The inner second ply has an inner end located axially inward of the inner end of the outer second ply, and has a substantially same length as the outer second ply in a tire cross-section.

In a pneumatic tire, a bead filler is radially outward of a bead core, a carcass turned up end is radially inward of an outer side end of the bead filler, the turned up end is spaced from a carcass body, a reinforcement layer is laterally outward of the bead filler, a sidewall rubber extends from a sidewall to the bead, an inner rubber reinforcing layer is between the bead filler and the reinforcement layer and adjacent to the turned up end, a crack suppression layer is between the reinforcement layer and the sidewall rubber, the crack suppression layer extends 5 mm or more from where the crack suppression layer overlaps, the reinforcement layer contacts the carcass body radially outwardly of the bead filler, and a 100% modulus Kc.sub.M100 of the crack suppression layer is at least 1.5 times that of the sidewall rubber.

A pneumatic tire mountable on a 15 tapered specified rim, the pneumatic tire including a bead portion, bead core, a carcass, a steel cord reinforcing layer, and a bead rubber layer. A distance from a second line segment to a third line segment is from 4 mm to 8 mm, and a ratio R2/R1 is from 0.935 to 0.975, wherein R2 is a tire radius at a bead toe of a bead base portion and R1 is a tire radius at a bead heel.

A pneumatic tire mountable on a 15 tapered specified rim includes a bead core, a carcass, a steel cord reinforcing layer, a bead rubber layer, an organic fiber reinforced layer, and a first reinforcing rubber layer. A distance from a second line segment to a third line segment is from 4 mm to 12 mm, a complex modulus of the first reinforcing rubber layer is from 6 MPa to 10 MPa, an elongation at break of the first reinforcing rubber layer is from 300% to 450%, and a difference between a first height and a second height is from 3 mm to 15 mm.

A pneumatic tire includes a bead portions and a bead core at the bead portions, the tire being mounted to a 15-tapered specified rim. The bead portions include a portion inward in a radial direction of an extension line of an inner circumferential surface of the bead core, the extension line extending in the lateral direction, that is positioned outward in the tire lateral direction of an imaginary line passing through a first intersection point between the extension line and a tire inner surface and extends inward in the tire radial direction from the extension line at an angle perpendicular to the extension line. An angle formed by the imaginary line and a line segment passing through a second intersection point between a bead base and the tire inner surface and the first intersection point between the extension line and the tire inner surface is from 0 to 25.