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 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%, a complex modulus of the second reinforcing rubber layer is from 10 MPa to 15 MPa, and a complex modulus of a shock absorbing rubber layer is from 2 MPa to 6 MPa.

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 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%, a complex modulus of the second reinforcing rubber layer is from 10 MPa to 15 MPa, and a complex modulus of a shock absorbing rubber layer is from 2 MPa to 6 MPa.

A pneumatic tire includes: paired bead portions respectively including annular bead cores and bead fillers disposed on an outer side in a tire radial direction of the bead cores; sidewall portions respectively extending outward in the tire radial direction from the bead portions; a tread portion connected to cuter ends in the tire radial direction of the sidewall portions to form a tread; and a carcass layer suspended between the bead portions. The carcass layer has a first ply that continuously extends between the bead portions and that has opposite end portions respectively and a second ply that continuously extends on the outer side in the tire radial direction of the first ply, wherein the first ply has higher tensile strength than that of the second ply, and the end portion is positioned on the outer side in the tire radial direction of the end.

In one aspect of a tire (10) of the present invention, a plurality of carcass plies (50a) include a first carcass ply (51). A first end portion (51a), which is a distal end portion of a portion of the first carcass ply folded around the bead core, is located outside in a tire radial direction from a position (WL) where a dimension in a tire width direction is maximum, and is located at a boundary portion (14) between a tread portion (11) and a sidewall portion (12), and in the portion located outside in the tire radial direction from the position where the dimension in the tire width direction is maximum, a dimension (T5) in a tire thickness direction between the portion of the first carcass ply folded around the bead core and an outer surface (12a) of the tire in the tire width direction is maximum between the first end portion and the outer surface of the tire in the tire width direction.

A pneumatic tire 1 has a carcass 6 extending between a first bead portion 4A and a second bead portion 4B through a tread portion 2 and a pair of sidewall portions 3. The carcass 6 is composed of at least two carcass plies 7 including a first carcass ply 7A and a second carcass ply 7B which have the same ply length. Each of the first carcass ply 7A and the second carcass ply 7B is arranged asymmetrically with respect to the tire equator C.

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 includes: paired bead portions respectively including annular bead cores and bead fillers disposed on an outer side in a tire radial direction of the bead cores; sidewall portions respectively extending outward in the tire radial direction from the bead portions; a tread portion connected to outer ends in the tire radial direction of the sidewall portions to form a tread; a carcass layer suspended between the bead portions; and a belt layer provided on an outer side in the tire radial direction of the carcass layer in the tread portion. The carcass layer has a first ply that continuously extends between the bead portions and that has opposite end portions and a second ply that extends from a position in contact with an inner peripheral face of an end portion, wherein the second ply has higher tensile strength than the tensile strength of the first ply.

The invention is a tyre comprising, in the central part of its crown, at least one undulation (51) of the radially outermost crown layer, having a radial amplitude A at least equal to 1 mm. At least one bead comprises, aside from the radial carcass layer and the bead wire, a radial reinforcing element that is such that the axial distance between the radial reinforcing element and the axially innermost carcass layer is at least equal to 1 mm and at most equal to 12 mm at the point of the radial reinforcing element that is situated 30 mm from the radially innermost point of the bead wire, for a better trade-off between the stiffness of the undulating crown and of the bead.

A pneumatic tire is provided. In a meridian cross-section, an external contour shape of the bead core is a polygon formed by common tangent lines of a plurality of circumferential portions of a bead wire, the external contour shape includes a single vertex located toward the outside in a tire radial direction, an internal angle formed by two sides sandwiching the vertex is an acute angle, a bottom side of the external contour shape is inclined with respect to the tire lateral direction by from 2° to 9°, and the carcass layer is bent and folded back along a circumference of the bead core in a bead portion, a folded back portion of the carcass layer from a position of an outer end of the bead core in the tire radial direction extends toward a sidewall portion in contact with a body portion.

In a pneumatic tire mountable on a 5°-tapered rim, a bottom of a bead core is inclined from 0°-5° in a direction in which the bottom diverges toward an outer side in a radial direction as the bottom extends from an inner side in the width direction toward an outer side in the width direction. Each bead portion includes a base, a toe, and a heel. The base is inclined from 8°-12° in a direction in which the bead base portion diverges toward the outer side in the radial direction as the base extends from the inner side toward the outer side in the width direction. The heel has a radius of curvature from 25-30 mm. A rim cushion rubber has a modulus at 100% elongation within a range from 5.0-8.0 MPa. The toe has a displacement between before and after mounting on the rim from 9.0-13.5 mm.