Improving the endurance of the beads (1) of a radial tire for a civil-engineering heavy vehicle by proposing a solution which blocks the propagation of the cracks initiated in the coating elastomer of the bead reinforcing layer (5), by inserting a cushion rubber (6) interposed between the coating elastomer of the carcass layer turn-up (312) and the coating elastomer of the bead reinforcing layer (5). The elastic modulus in extension of the cushion rubber (6) measured at 100% deformation must be less than the elastic modulus of the coating compound of the carcass layer. Still according to a disclosed embodiment, the thickness of the cushion rubber (6) is at least equal to the thickness of the bead reinforcing layer (5).

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.

In this pneumatic tire, the bead core has a predetermined wire array structure obtained by arranging wire cross-sections of bead wires in a cross-sectional view in a tire meridian direction. The following are defined in the wire array structure: a tangent line that contacts, from the side of a rim fitting face, an innermost layer in the tire radial direction and the wire cross-section on the innermost side and the outermost side in the tire lateral direction; contact points of the tangent line with respect to the wire cross-sections on the innermost side and the outermost side; a middle point of the contact points; and gauges in the tire radial direction from the contact points and middle point to the rim fitting face. In this case, the change rates of the gauges before and after rim assembly each are in the range of 10% to 60%.

In a pneumatic tire, bead cores have a wire arrangement. In a cross-sectional view in a tire meridian direction, a tangential line and a contact point are defined. The tangential line contacts an innermost layer in a radial direction and the wire cross sections innermost and outermost in a lateral direction in the wire arrangement from a rim fitting surface side. The contact point of the tangent line is on the wire cross section on the outermost side. A gauge Wh in the lateral direction from the contact point to the rim fitting surface and an outer diameter φ of the bead wire have a relationship 2.0≤Wh/φ≤15.0. A radial height H2 of a contact portion between a body portion and a turned back portion of a carcass layer has a relationship 0.80≤H2/H1≤3.00 to a radial height H1 of the bead cores.

To provide a tire rubber composition that is capable of producing a tire that is excellent in balance between the low heat generation property and the crack resistance. The tire rubber composition contains a rubber component (A), at least one compound (B) selected from the group consisting of a compound represented by the formula (I) and a compound represented by the formula (II), a vulcanization accelerator (C) containing two or more kinds of vulcanization accelerators including a thiuram-based vulcanization accelerator, and a filler (D).

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A pneumatic tire comprises a carcass which comprises a carcass ply composed of a main portion extending between bead portions and a pair of turned-up portions turned-up around respective bead cores. The bead portion is provided with: a primary bead apex rubber disposed between the carcass-ply main portion and the carcass-ply turned-up portion; an insulation rubber layer extending radially outwardly through between the carcass-ply main portion and the carcass-ply turned-up portion; and a subsidiary bead apex rubber layer disposed on the axially outside of the carcass-ply turned-up portion. The radially outer edge of the insulation rubber layer is located radially outside the radially outer edge of the subsidiary bead apex rubber layer. The complex elastic modulus of the insulation rubber layer is equal to or greater than the complex elastic modulus of the topping rubber of the carcass ply.

A pneumatic tire comprises a carcass ply extending between bead portions through a tread portion and sidewall portions, and turned up around a bead core from the inside to the outside of the tire in each of the bead portions, so as to form a pair of turnup portions and a main portion therebetween. In each the bead portion, a first apex rubber and a second apex rubber are disposed. The first apex rubber is disposed between the turnup portion and the main portion. The second apex rubber is disposed axially outside the turnup portion. A complex elastic modulus b of the second apex rubber is larger than that of the first apex rubber. The cross-sectional width wt in mm of the tire and the outer diameter Dt in mm of the tire satisfy the following conditions Dt=<59.078×wt.sup.0.498 and Dt>=59.078×wt.sup.0.460.

A heavy goods vehicle tire has a radial carcass reinforcement, made up of a single layer of metal reinforcing elements anchored in each of the beads by a turn-up around a bead wire. The turn-up of the carcass reinforcement layer and the main part of the carcass reinforcement layer are coupled, and a passive radiofrequency communication module is placed facing the coupling region at the interface between two layers of rubber compounds.

A pneumatic tire comprises: a bead portion provided with an inside bead apex rubber disposed between a turned up portion and a main portion of a carcass ply, and an outside bead apex rubber disposed axially outside the turned up portion and having a radially outer edge; and a the sidewall portion provided with a sidewall reinforcing cord layer disposed axially outside the carcass and having a radially inner edge which is spaced apart from the radially outer edge of the outside bead apex rubber by a radial distance of not less than 5% of a tire section height.

A tire includes: a pair of beads having bead cores and a bead filler extending to an outer side in a tire-radial direction of the bead core; a carcass ply extending from one of the bead core of one bead to the bead core of the other bead, and folded back around each of the bead cores; a first pad disposed at an outer side in a tire-width direction of a folding end of the carcass ply which is folded back; a second pad disposed at an outer side in the tire-width direction of the first pad; and rim strip rubber disposed at least at a part on an outer side in the tire-width direction of the second pad, in which an electronic component is provided to interpose the second pad and the rim strip rubber.