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.

Process for manufacturing a tyre, includes the following steps: (a) winding at least one metal wire so as to form a plurality of coils, the coils being radially superimposed and axially arranged side-by-side with respect to one another, so as to obtain a bead core; (b) applying at least one layer of a crosslinkable elastomeric material to the bead core obtained in step (a), so as to obtain a coated bead core; (c) partially crosslinking the at least one layer of crosslinkable elastomeric material, so as to obtain an amount of free sulfur of 30% by weight to 70% by weight, preferably of 40% by weight to 65% by weight, more preferably of 50% by weight to 60% by weight, with respect to the total weight of the sulfur present in the crosslinkable elastomeric material; and (d) applying a bead filler to the radial outer surface of the bead core obtained in step (c), so as to obtain a bead structure for a green tyre.

A bead member includes an annular bead filler made of a resin, and a deformation facilitating portion configured to facilitate an axial deformation is provided at a portion of the bead filler in a radial direction.

The tire has a load index that is at least 118 and two layers of reinforcing elements. Each of the layers has a breaking force per unit width that is higher than 2900 daN/dm. A minimum strength per unit width, measured for an elongation of less than 10%, of the second layer is greater than 20% of the minimum strength per unit width, measured for an elongation of less than 10%, of the first layer. The reinforcing elements of the first layer have a thread count that is higher than 300 tex. The reinforcing elements of the two layers have a thread count of less than 750 tex. The elongation of the reinforcing elements of the second layer are greater than 8% under a force of 20 daN and the secant elastic modulus values under tension at 10% elongation, Mt, Mj, satisfy the relationship Mt/Mj1.

Each of at least two layers of a carcass reinforcement has a breaking force per unit width higher than 2250 daN/dm. The minimum strength per unit width, measured for an elongation of less than 10%, of a second layer of carcass reinforcement is strictly greater than a value equal to 20% of the minimum strength per unit width, measured for an elongation of less than 10%, of a first layer of carcass reinforcement. The reinforcing elements of the two layers of carcass reinforcement have a thread count of less than 750 tex. The elongation of the reinforcing elements of the second layer of carcass reinforcement is greater than 4% under a force of 20 daN, and the secant elastic modulus values under tension at 10% elongation, Mt, Mj, satisfy the relationship Mt/Mj1.

A bead member manufacturing method in the present invention includes a bead core forming step of winding and stacking a bead wire from a winding start end to a winding finish end and forming a bead core having an annular shape, the bead wire being formed by coating an outer circumferential surface of a metal wire with a topping rubber; and a bead wire banding step of winding a tape-shaped rubber around one or both of the winding start end and the winding finish end, wherein tackiness of the tape-shaped rubber is higher than tackiness of the topping rubber.

A tire for a motor vehicle having at least one carcass ply comprised of a crown portion and two axially opposite side portions terminating in beads for mounting the tire on a rim. A tread band and a belt structure are interposed between the carcass structure and the bead. Each bead includes on elongated cord comprised of a first yarn, such as aramid, having a melting or decomposition point T.sub.1, and a second yarn, such as nylon, having a melting point T.sub.2, wherein T.sub.1>T.sub.2, and T.sub.2 is greater than 40 C.

A heavy load tire includes a bead core formed by a bead wire wound plural times in a ring shape, and a rubber sheet formed of a rubber material. The rubber sheet is wound on a region including one end portion and another end portion of the bead wire. The one end portion is served as an end portion closest to another end portion in a tire circumferential direction.

Disclosed herein is a bead reinforcing device for pneumatic tires, which includes a bead forming a circumference of a tire as a portion where the tire is in contact with a wheel, a carcass formed to cover the bead from its inside to its outside and forming an entire frame of the tire, and a bead stiffener formed to cover an entire outer surface of the bead.

A tire 2 includes a pair of beads 12 and a carcass 14. A core 28 of each bead 12 includes a body 34 having a hexagonal cross-section, and a cover 36 covering the body 34. The cover 36 is wrapped around the body 34, and the number of turns the cover 36 is wrapped around the body 34 is greater than or equal to one and smaller than two. The cover 36 includes a plain weave fabric obtained by interlacing warp threads 72 and weft threads 74. The warp threads 72 and the weft threads 74 intersect. An angle of the intersection is greater than or equal to 45 and not greater than 125. The warp threads 72 are inclined relative to a carcass cord 70. An angle of the inclination is greater than or equal to 22.5 and not greater than 67.5.