The present invention provides a run-flat tire excellent in high-temperature softening inhibition, and a rubber composition from which the tire can be produced. The rubber composition contains a rubber component, a filler, a vulcanizing agent, and a vulcanization accelerator that contains a sulfenamide-based vulcanization accelerator and 1.0 to 2.0 parts by mass of tetrabenzylthiuramdisulfide based on 100 parts by mass of the rubber component, in which a mass ratio (a/b) of a content (a) of the tetrabenzylthiuramdisulfide to a content (b) of the sulfenamide-based vulcanization accelerator is 0.60 to 1.25.

A tire fitted with a transponder comprises: a crown comprising a crown reinforcement having an axial end at each of its edges, connected at each of its axial ends by a sidewall to a bead having an interior end; a carcass reinforcement, formed of adjacent first threads, which is anchored in each bead around a spiral formed by second threads; and the transponder comprising a dipole antenna consisting of a spring defined by a pitch P and a diameter D. A ratio between the pitch (P1) and the diameter (D1) for a loop of a first region of the spring is greater than 0.8, and the transponder is situated axially on the outside of an interior end of the bead and radially between the upper end of the spiral and the axial end of the crown reinforcement.

A tire can include a tread, sidewalls, beads, and a carcass. Each bead can include a core and an apex. A ratio of a height of the apex to a cross-sectional height of the tire may be not less than 5% and not greater than 15%. In a meridian cross-section of the tire in a standard state, a contour of a side surface including a maximum width position can include two arcs tangent to each other at the maximum width position. The arc located inward of the maximum width position in a radial direction can be a first arc, and the arc located outward of the maximum width position in the radial direction can be a second arc. A ratio of a first radius of the first arc to a second radius of the second arc may be not less than 70% and not greater than 91%.

With a pneumatic tire not mounted on a rim, in a meridian cross-section a first line is parallel with an innermost bottom side of a bead core in a radial direction and passes through an outermost projection of the bead core in a lateral direction, a second line is orthogonal with the first line at the outermost projection, a third line is orthogonal with the first line and passes through an intersection of a rim cushion rubber, a distance between the second and third lines is 2.0 to 4.0 mm, a shortest distance between an innermost projection of the bead core in the lateral direction and a cord of a carcass layer is 0.6 to 1.4 mm, and a shortest distance between an innermost end of the bottom side of the bead core in the lateral direction and the cord of the carcass layer is 1.2 to 2.2 mm.

Disclosed is a method for manufacturing a pneumatic tire including a tread, sidewalls and a first bead and a second bead, which beads are spaced apart, the first bead and the second bead including: a drop shaped bead core , the drop shaped bead core having a cross sectional area including or consisting of a circular portion and a tapering portion, and an apex positioned adjacent and/or against the bead core, the method including: connecting the apex to the drop shaped bead core, thereby obtaining an assembly including the drop shaped bead core and the apex, pre-forming a tire including the assembly, and vulcanizing the pre-formed tire, thereby obtaining the pneumatic tire. Also disclosed is a pneumatic tire.

A pneumatic tire having a pair of bead portions are each composed of an annular bead core made of a thermoplastic resin, and a bead core covering portion made of a thermoplastic resin.

A bead portion of a pneumatic tire includes an annular bead structure in which a core part in which a bead core is covered with a resin, and a bead filler which is formed of a resin, are integrally formed. A plurality of concave portions and a plurality of convex portions are formed on a surface of the bead structure. Each of the concave portions is extended to and communicated with a tire radial direction outside end of the bead structure.

The tire has s bead structure including a bead core portion having a cord unit and a bead filler portion continuous to the bead core portion in the tire radial direction outside of the bead core portion and formed of a resin material. The bead filler portion has a tip portion which becomes thinner toward outside in the tire radial direction. The tip portion is positioned inside in the tire width direction inside than a straight line passing through a center in the width direction at an inside end in the tire radial direction of the bead core portion and passing through a center in the width direction at outside end in the tire radial direction of the bead core portion.

In a tire or a tire manufacturing method, a bead section includes a bead member formed by integrally molding a bead core, in which a resin material covers bead cords, and a bead filler made with a resin material covering the bead core, and around which a carcass ply, in the tire, is folded. In a cross-section along a tire widthwise direction and a tire radial direction of the bead member, the bead core is arranged by being shifted with respect to a width-directional center of the bead member.

In a tire 2, a length from a center in an axial direction of a boundary between a core 30 and an apex 32 of each bead 10 to an outer end PA of the apex 32 is not less than 10 mm and not greater than 15 mm. In a state where the tire 2 is mounted on a normal rim and an internal pressure of the tire 2 is adjusted to a normal internal pressure, a shape of a main body portion 36, of a carcass ply 34, which is located in a zone from a boundary portion between a tread 4 and each sidewall 6 to the outer end PA of each apex 32 is represented by a single circular arc, and a diameter of the circular arc is not less than 75% and not greater than 90% of a cross-sectional height of a carcass 14.