In a cross-section of a pneumatic tire, a contour of the bead core is a polygon formed by tangent lines of circumferential portions of a bead wire, the contour includes a vertex with an acute angle and a bottom side opposite the vertex, the carcass layer is folded back along a circumference of the bead core in a bead portion, a folded back portion of the carcass layer from an outer end of the bead core extends in the radial direction, and a distance in the radial direction between a center of an arc profile of a tire outer surface and a straight line extending in the lateral direction through the vertex is within 20% of a radius r of the arc, and a distance in the lateral direction between the center of the arc and a straight line extending in the radial direction through the vertex is within 2r±0.4r.

In a tire 2, on a cross-section, three or more rows in each of which cross-sections 30 of a wire are aligned almost in the axial direction, are layered in the radial direction. The cross-sections 30 of the wire in a first row disposed on an innermost side in the radial direction and the cross-sections 30 of the wire in a second row layered outward of the first row are staggered. On a cross-section obtained by the tire 2 being cut at a plane perpendicular to the circumferential direction, an outline of a heel surface 36 of a bead 8 portion has an arc C that projects toward an outside of the bead 8 portion. A radius R of curvature of the arc C is greater than or equal to 8 mm and not greater than 12 mm.

A pneumatic tyre comprises a tread portion, a pair of opposing sidewall portions and a pair of opposing bead portions, the tread portion extending radially outwards from the sidewall portions and the sidewall portions extending radially outwards from the bead portions, wherein each bead portion comprises an axially inward side and an axially outward side which are joined at a base of the bead portion and each axially outward side of the bead portion comprises a concave region extending axially inwards. Each concave region further comprises a convex region located within the concave region which extends axially outwards.

A pneumatic tyre comprises a tread portion, a pair of opposing sidewall portions and a pair of opposing bead portions, the tread portion extending radially outwards from the sidewall portions and the sidewall portions extending radially outwards from the bead portions, wherein each bead portion comprises an axially inward side and an axially outward side which are joined at a base of the bead portion and each axially outward side of the bead portion comprises a concave region extending axially inwards. Each concave region further comprises a convex region located within the concave region which extends axially outwards.

A tire for a heavy vehicle with a radial carcass reinforcement anchored in two beads by wrapping around bead wires. In a radial plane, radially on the inside of the radially innermost point of the at least one layer of carcass reinforcement and axially on the outside of the geometric center of the bead wire, the radius of curvature at a point on the exterior surface of the bead is greater than the radius of curvature at the point of orthogonal projection of the point of the exterior surface of the bead onto the at least one layer of carcass reinforcement.

A tire for a heavy vehicle with a radial carcass reinforcement anchored in two beads by wrapping around bead wires. In a radial plane, radially on the inside of the radially innermost point of the at least one layer of carcass reinforcement and axially on the outside of the geometric center of the bead wire, the radius of curvature at a point on the exterior surface of the bead is greater than the radius of curvature at the point of orthogonal projection of the point of the exterior surface of the bead onto the at least one layer of carcass reinforcement.

In a pneumatic tire on a rim with 5° taper, a bead core includes a bead core bottom inclined 0° to 5° with respect to a rotation axis in a direction in which the bead core bottom extends outward in a radial direction from an inner side toward an outer side in the lateral direction, a bead portion includes a bead base portion inclined 8° to 12° with respect to the rotation axis in a direction in which the bead base portion extends outward in the radial direction from the inner side toward the outer side in the lateral direction. A bead width BW is a distance between tire inner and outer surfaces on a straight line through a bead core center in the meridian cross-section and parallel to the bead base portion. The bead core has a maximum width CW within a range of (BW×0.54)≤CW≤(BW×0.58).

A pneumatic tire comprises: a tread portion; a pair of sidewall portions; a pair of bead portions each with a bead core embedded therein; a toroidal carcass extending between the bead portions; and a sidewall rubber disposed axially outside the carcass in each of the sidewall portions. The bead portion has a bead bottom surface which contacts with a bead seat of a wheel rim when the tire is mounted thereon. The bead bottom surface comprises an axially inner region including a bead toe and an axially outer region including a bead heel. The axially inner region is formed by a canvas chafer. The axially outer region is formed by the sidewall rubber extended radially inwardly from the sidewall portion.

A pneumatic tire comprises: a tread portion; a pair of sidewall portions; a pair of bead portions each with a bead core embedded therein; a toroidal carcass extending between the bead portions; and a sidewall rubber disposed axially outside the carcass in each of the sidewall portions. The bead portion has a bead bottom surface which contacts with a bead seat of a wheel rim when the tire is mounted thereon. The bead bottom surface comprises an axially inner region including a bead toe and an axially outer region including a bead heel. The axially inner region is formed by a canvas chafer. The axially outer region is formed by the sidewall rubber extended radially inwardly from the sidewall portion.

In a pneumatic tire, a carcass layer is between bead portions, a bead core is in each bead portion, a reinforcement layer is on an outer side of the carcass layer, and a tread rubber layer is on the outer side of the reinforcement layer. A pair of first boundary lines passes through an intersection of an extension of a side arc forming a tread profile and an extension of a shoulder arc and orthogonal to a tire inner surface, a pair of second boundary lines passes through a rim check line and orthogonal to the tire inner surface, first to third regions are defined which have cross sectional areas of SA, SB, and SC, respectively, and the first to third regions respectively have lengths of a, b, and c along the tire inner surface such that 7.5≤SA/a≤11.5 and 2.0≤SB/b≤6.0 are satisfied.