A pneumatic tire, comprising at least sidewall portions and rim guards each provided at the corresponding sidewall portion, wherein: in a cross section in the width direction of the tire assembled with a prescribed rim, an outer contour line, of the rim guard, situated on the outer side in the tire radial direction than the radially outermost peak of the rim guard has an arcuate configuration of which the center of curvature is located on the external side of the tire; radius of curvature R of the outer contour line is in the range of 5 mm≦R≦40 mm; and provided that H represents a distance in the tire radial direction measured from the radially innermost peak to the outermost position in the tire radial direction of a rim flange, 2 mm≦H≦40 mm.

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 a pneumatic tire, a bead filler is on an outer circumference of a bead core, a carcass turned up end is inward of an outer diameter side end of the bead filler, the carcass end is spaced from a carcass body, a steel reinforcement is in each bead, a sidewall rubber extends from the sidewall to the bead, and a support layer is between the bead filler and the sidewall rubber to cover the carcass end and an end of the steel reinforcement, the support layer extending toward an outer diameter side and contacting the carcass body on an outer diameter side of the bead filler outer diameter side end, and a 100% modulus of the support layer is at least 1.5 times that of the bead filler, and the sidewall rubber, the bead filler and the sidewall rubber being adjacent to the support layer.

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.

In a tire 2, each of sidewalls 6 includes a first layer 36 disposed axially outward of a corresponding one of beads 8, and a second layer 38 extending outward from the first layer 36 in a radial direction. When Pc represents a position of an axially outer end of an interface between a carcass 10 and the sidewall 6, an outer end 40 of the first layer 36 is disposed radially inward of the position Pc. A hardness H1 of the first layer 36 is greater than a hardness H2 of the second layer 38. A ratio (H2/H1) of the hardness H2 to the hardness H1 is preferably not less than 0.70 and preferably not greater than 0.95.

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.

A tire includes a tread, a pair of sidewalls, a pair of beads, and a carcass. Each bead includes a core and an apex. In the tire in the normal state, a ratio (HA/HS) of a distance HA in a radial direction from a bead base line to an outer end PA of the apex to a tire cross-sectional height HS may not be less than 20% and/or may not be greater than 30%, and an angle of a line segment connecting between the outer end PA of the apex and a center PM of a width, in an axial direction, of a contact surface of the apex at which the apex is in contact with the core, relative to the bead base line, may not be less than 45° and/or may not be greater than 55°.

A run-flat tire includes a side reinforcing rubber layer, a first bead filler on an inner side of a carcass turned-up portion in a width direction, and a second bead filler on an outer side of the carcass turned-up portion in the width direction. A first bead filler height is 30% or less of a tire cross-sectional height SH. A second bead filler height is 50% or greater of the height SH. A cross-sectional area of the second bead filler is from 150% to 400% of a cross-sectional area of the first bead filler. A relationship (0.16×SH×LI−1100)≤S.sub.ALL≤(0.16×SH×LI−800) is satisfied, where S.sub.ALL represents a sum of cross-sectional areas of the side reinforcing rubber layer and the first and second bead fillers, and LI represents a load index.

A run-flat tire includes reinforcing rubber in a sidewall, first bead filler rubber disposed toward the inside of a folded back portion of a carcass layer in a lateral direction, and second bead filler rubber disposed toward the outside of the folded back portion in the lateral direction. The reinforcing rubber has a thickness from a rim base line to a position within 38% to 68% of a tire cross-sectional height being from 90% to 100% of a maximum thickness of the reinforcing rubber. In a range from a position of a rim check line to a position being 38% of the tire cross-sectional height from the rim base line, a total thickness of the reinforcing rubber, the first bead filler rubber, and the second bead filler rubber is from 100% to 140% of the maximum thickness of the reinforcing rubber.

Provided is a tire 2 that can achieve reduction of rolling resistance while reducing a decrease in durability to be small. An apex 32 of each bead 10 includes an apex body 48, a strip apex 50, and an intermediate apex 52. An inner end of the strip apex 50 is located between a ply body 38a of a carcass ply 38 and the apex body 48. An inner end of the intermediate apex 52 is located between the strip apex 50 and the apex body 48. An outer end of the apex body 48 is located between the inner and outer ends of the intermediate apex 52. The intermediate apex 52 is located between the inner and outer ends of the strip apex 50. The intermediate apex 52 is harder than the apex body 48, and the strip apex 50 is harder than the intermediate apex 52.