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, and a first reinforcing rubber layer. A distance from a second line segment to a third line segment is from 4 mm to 8 mm; a side of an outer portion and a side of an inner portion of a bead base portion bend at an inflection point located in a range from 8 mm to 18 mm from the first intersection point; and an angle γ formed by an extension line drawn from the side of the outer portion inward in the tire radial direction and the side of the inner portion is from 4.5° to 14.5°.

A pneumatic tyre includes a carcass extending between bead cores disposed in respective bead portions through a tread portion and sidewall portions, and bead apex rubbers each extending radially outwardly from the respective bead cores, each bead apex rubber having an inner side surface in a tyre axial direction. In a tyre cross-section under a standard inflated state, a ratio h1/H of a carcass-maximum-width height h1 to a carcass-maximum height H is equal to or less than 50%, and in at least one bead portion, an angle of a tangent line touching the inner surface of the bead apex rubber at an intersection of a tyre radial reference line passing a rim-width location of the standard wheel with the inner side surface of the bead apex rubber is in a range of from 55 to 75 degrees to the tyre radial reference line.

A pneumatic tire includes a pair of bead portions. Each bead portion has a bead core, and a chafer rubber arranged axially inside the bead core and extending outward in a tire radial direction from a bead toe along a tire inner cavity surface. The chafer rubber is formed of a rubber composition not including fiber material for reinforcement.

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.

A pneumatic tire includes a pair of bead portions that are arranged at intervals wider than a regular rim width in a non-rim-assembled state. The bead portion includes a rim protector, a bead base, a bead heel, and a bead back surface. In the non-rim-assembled state, the bead back surface is formed with a recess that is recessed inward in the tire width direction. The bead back surface has a second curved portion constituting a deepest portion of the recess and a third curved portion extending inward in the tire width direction from the rim protector. When a height of the deepest portion is H2, a height H8 of a virtual intersection of a curve obtained by extending the second curved portion and a curve obtained by extending the third curved portion is larger than 1.5 times H10 and smaller than 3.0 times H10.

A pneumatic tire having a side portion and a clinch portion, wherein: in a meridian cross section, the distance from a bead baseline to the outside portion in the width direction of the clinch portion is greater than the distance to the inside portion in the width direction; the E*.sub.S of the side portion, as measured at 70° C., a frequency of 10 Hz, an initial distortion of 5%, and a distortion rate of 1%, is less than the E*.sub.C of the clinch portion; and, formulas (1) and (2) are satisfied:

1600≤(Dt.sup.2×π/4)/Wt≤2827.4  (1)

[(V+1.5×10.sup.7)/Wt]≤2.88×10.sup.5  (2)

where Wt is the cross-sectional width of the tire installed on a standardized rim and filled with air to an internal pressure of 250 kPa, Dt is the outer diameter, and V is the volume of the tire.

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

In a tire 22, a length from a center PM in an axial direction of a boundary 60 between a core 48 and an apex 50 to an outer edge PA of the apex 50 is not less than 10 mm and not greater than 15 mm. In a state where the tire 22 is mounted on a normal rim and an internal pressure of the tire 22 is adjusted to 10% of a normal internal pressure, a main body portion 54 of a carcass ply 52 extending along an inner surface 62 of the apex 50 is tilted relative to the axial direction, and an angle of the main body portion 54 relative to the axial direction is not less than 40° and not greater than 60°.

A pneumatic tyre includes a tread portion provided with circumferential grooves to form circumferential land portions, a belt layer, and a band layer disposed outwardly in the tyre radial direction of the belt layer. The band layer includes a first layer covering an entire width of the belt layer, and second layers disposed outwardly in the tyre radial direction of the first layer and arranged separately in a tyre axially direction from one another. Each second layer is located radially inwardly of a respective one of the circumferential land portions. In each circumferential land portion, the second layer has at least one axial edge that is away at a distance (A) of equal to or more than 3.0 mm in the tyre axial direction from a groove bottom of one of the circumferential grooves nearest to the at least one axial edge.

A pneumatic tire comprises: a tread portion; a pair of sidewall portions; a pair of bead portions each with a bead core embedded therein; a toroidal carcass extending between the bead portions; and a sidewall rubber disposed axially outside the carcass in each of the sidewall portions. The bead portion has a bead bottom surface which contacts with a bead seat of a wheel rim when the tire is mounted thereon. The bead bottom surface comprises an axially inner region including a bead toe and an axially outer region including a bead heel. The axially inner region is formed by a canvas chafer. The axially outer region is formed by the sidewall rubber extended radially inwardly from the sidewall portion.