A tire has a form of a torus that is open radially on an inside portion. The tire includes inner and outer walls, a crown, two sidewalls, two beads, a crown reinforcement, and a carcass reinforcement anchored in the beads and extending at least from the beads as far as the crown. The inner wall is covered at least in part with an airtight layer, and the airtight layer is covered at least in part with a layer of a self-sealing product. Each of the beads includes an annular reinforcing structure, with each annular reinforcing structure being formed of a plurality of windings of a single metal thread. The windings are arranged in a plurality of radially superposed layers, with each layer having a group of the windings arranged axially in a side by side manner, such that the superposed layers have a hexagonal cross section.

A method for predicting a pressing force of a bead portion of a tire having a bead core in the bead portion, comprises a step of predicting the pressing force of the bead portion when the tire is fitted onto a rim of a wheel by using a numeric expression including at least the inner diameter of the bead core, the diameter of the rim, and the thickness inward in the tire radial direction from the bead core.

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.

The bead wire (52) comprises several windings of wire and a basic hexagonal bead wire (56) comprising: two axially and radially external lateral rows (F1, F2) of N2 windings, two axially external and radially internal lateral rows (F3, F4) of N2 windings, where N1=N2+1 or N1=N2, two junctions (J1, J2), each formed by a winding that an axially and radially external lateral row (F1, F2) and an axially external and radially internal lateral row (F3, F4), have in common, each winding in common having no winding of wire axially on the outside of it. The bead wire (52) comprises two axially and radially external additional lateral rows (A1, A2) of N3 windings substantially parallel respectively to each axially and radially external lateral row (F1, F2).

The bead wire (52) comprises several windings of wire and a basic hexagonal bead wire (56) comprising: two axially and radially external lateral rows (F1, F2) of N2 windings, two axially external and radially internal lateral rows (F3, F4) of N2 windings, where N1=N2+1 or N1=N2, two junctions (J1, J2), each formed by a winding that an axially and radially external lateral row (F1, F2) and an axially external and radially internal lateral row (F3, F4), have in common, each winding in common having no winding of wire axially on the outside of it. The bead wire (52) comprises two axially and radially external additional lateral rows (A1, A2) of N3 windings substantially parallel respectively to each axially and radially external lateral row (F1, F2).

A pneumatic tire includes a bead core including circumferential portions made of metal wire bundled in rows disposed at each bead portion; and a carcass layer turned up at end portions around the bead cores from a tire inner side to an outer side; the bead cores including at least two central layers centrally located in a tire radial direction, at least one upper layer outward of the central layers in the radial direction, and at least one lower layer inward of the central layers in the radial direction; a number of the circumferential portions made of metal wire in the central layers is equal to each other and a maximum value; and a number of the circumferential portions made of metal wire in the upper layer(s) and the lower layer(s) being reduced by one from the maximum value for each layer away from the central layers.

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 8 mm; a side of an outer portion and a side of an inner portion of a bead base portion bend at an inflection point located in a range from 8 mm to 18 mm from the first intersection point; and an angle formed by an extension line drawn from the side of the outer portion inward in the tire radial direction and the side of the inner portion is from 4.5 to 14.5.

A vehicle tire having two beads comprising metal/non-metal hybrid bead cores intended to come into contact with a wheel rim and a carcass reinforcement anchored by a bead core located in each bead, wherein the bead core includes a plurality of separate spirally-wound reinforcements that are placed adjacent to one another in a substantially axial arrangement. The innermost of the spirally-wound reinforcements, the one farthest from the reinforcement turn-up, is formed of a first metal wire and there is a non-metallic wire forming a second reinforcement. The metal wire has an elongation at break that is at least 40% greater than an elongation at break of the nonmetallic wire or alternatively at least 100% or at least 200% greater than the elongation at break of the non-metallic wire. Optionally wires of other metals or nonmetals may be useful for forming others of the plurality of spirally-wound reinforcements.

A pneumatic tire 1 is provided in a bead portion 4 with a bead core 5 formed of a bead wire 20. The bead core 5 has a wound single bead wire structure formed from turns of the single bead wire 20, and has at least three wire layers 10. Each side face of the bead core 5 has a shape such that it is possible to draw a common tangent 30 to at least two turns of the bead wire 20 appearing in the side face 51 which common tangent is substantially parallel with the tire radial direction. The turns of the bead wire 21 in the 1st wire layer 11 are alternated with the turns of the bead wire 22 in the 2nd wire layer 12 disposed on the outside of the 1st wire layer 11. The 1st wire layer 11 includes a turn 21 having the winding-start end 16 of the bead wire, which turn 21 is positioned between adjacent two turns 22 of the bead wire in the 2nd wire layer 12.

A bead core for a tire, which is substantially rotationally symmetrical about an axis, comprises a plurality of windings of at least one metallic wire with diameter d arranged next to one another in a direction P forming an angle with the axial direction in a radial sectional half-plane R, on N layers superposed on one another in the radial direction, wherein: ranges from 0 to 10; in the sectional half-plane R, the windings form a structure consisting of a base structure and a cap structure, wherein the radially inner base structure in the shape of a parallelogram is directly in contact in the radial direction with the radially outer cap structure in the shape of a trapezium. The product of the diameter d times the number of windings L ranges from 13.0 mm to 25.0 mm, and N is less than or equal to 16.