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 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%.

A tire having a radial carcass reinforcement, made up of a single layer of reinforcing elements anchored in each of the beads by being turned up around a bead wire, reinforced by a stiffener. The two working crown layers are the only ones present to form the crown reinforcement over at least 75% of the width of the tread, the absolute value of the difference between the absolute values of the angles α2 and α1 being greater than 7°, α2 being greater than α1 in terms of absolute value, the mean angle α satisfying the relationship 13+131*exp(−L/100)<α<28+110*exp(−L/100), the reinforcing elements of the carcass reinforcement being cords which, in the test referred to as the permeability test, yield a flow rate of less than 20 cm.sup.3/min, a rubber compound being present within the cords, and, in the sidewall of the tire, the profile of the outer surface of the tire is at a constant distance from the carcass reinforcement layer between the points F and A, and meets the outer surface of the bead at the point C, forming two successive circular arcs.

A tire having a radial carcass reinforcement, made up of a single layer of reinforcing elements anchored in each of the beads by being turned up around a bead wire, reinforced by a stiffener. The two working crown layers are the only ones present to form the crown reinforcement over at least 75% of the width of the tread, the absolute value of the difference between the absolute values of the angles α2 and α1 being greater than 7°, α2 being greater than α1 in terms of absolute value, the mean angle α satisfying the relationship 13+131*exp(−L/100)<α<28+110*exp(−L/100), the reinforcing elements of the carcass reinforcement being cords which, in the test referred to as the permeability test, yield a flow rate of less than 20 cm.sup.3/min, a rubber compound being present within the cords, and, in the sidewall of the tire, the profile of the outer surface of the tire is at a constant distance from the carcass reinforcement layer between the points F and A, and meets the outer surface of the bead at the point C, forming two successive circular arcs.

A heavy duty pneumatic tire includes a pair of beads, a carcass and a pair of bead fillers laminated outward with respect to the beads in the axial direction, respectively. Each bead includes a core and an apex, the carcass includes a carcass ply folded back around the core and having a main portion and a folding-back portion, each bead filler has an outer edge, an inner edge and a fitting portion to fit to a rim, the fitting portion includes a bottom surface to make contact with a seat surface of the rim and an outer-side contact surface to make contact with a flange of the rim, and the outer-side contact surface has inner-side, outer-side and middle portions such that when not mounted to the rim, the middle portion is recessed inward with respect to imaginary straight line L1 passing through outer edges of the inner-side and outer-side portions.

A heavy duty pneumatic tire includes a pair of beads, a carcass and a pair of bead fillers laminated outward with respect to the beads in the axial direction, respectively. Each bead includes a core and an apex, the carcass includes a carcass ply folded back around the core and having a main portion and a folding-back portion, each bead filler has an outer edge, an inner edge and a fitting portion to fit to a rim, the fitting portion includes a bottom surface to make contact with a seat surface of the rim and an outer-side contact surface to make contact with a flange of the rim, and the outer-side contact surface has inner-side, outer-side and middle portions such that when not mounted to the rim, the middle portion is recessed inward with respect to imaginary straight line L1 passing through outer edges of the inner-side and outer-side portions.

A tire includes a tread portion, a sidewall portion, and a bead portion. The bead portion includes a bead core that extends continuously in an annular shape in a tire circumferential direction, and a bead filler disposed adjacent to the bead core and outside the bead core in a tire radial direction. Reinforcing cords are provided in the bead portion and the sidewall portion so as to be curved such that inclination angles of the reinforcing cords with respect to the tire circumferential direction gradually increase with nearness to an outside in the tire radial direction.

A tire 2 includes a bead portion 2B to be fitted onto a rim R. The bead portion 2B includes a first vent line 50 extending in a circumferential direction, a second vent line 52 located outward of the first vent line 50 and extending in the circumferential direction, a columnar protrusion 54 located outward of the second vent line 52, and a saw cut 56 extending between the first vent line 50 and the columnar protrusion 54 and intersecting the second vent line 52. The first vent line 50, the second vent line 52, the columnar protrusion 54, and the saw cut 56 project from an outer surface of the bead portion 2B. The second vent line 52 is located on the columnar protrusion 54 side with respect to a midpoint LC between the first vent line 50 and the columnar protrusion 54.

A tire 2 includes a bead portion 2B to be fitted onto a rim R. The bead portion 2B includes a first vent line 50 extending in a circumferential direction, a second vent line 52 located outward of the first vent line 50 and extending in the circumferential direction, a columnar protrusion 54 located outward of the second vent line 52, and a saw cut 56 extending between the first vent line 50 and the columnar protrusion 54 and intersecting the second vent line 52. The first vent line 50, the second vent line 52, the columnar protrusion 54, and the saw cut 56 project from an outer surface of the bead portion 2B. The second vent line 52 is located on the columnar protrusion 54 side with respect to a midpoint LC between the first vent line 50 and the columnar protrusion 54.

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.