A pneumatic tires include a tread, a pair of sidewalls, and a pair of bead portions that are arranged at intervals wider than a rim width of a corresponding regular rim in a non-rim-assembled state. Each of the pair of bead portions includes a bead heel that curves outwards toward the outer side in the width direction and a bead back surface. In the non-rim-assembled state, the bead back surface is formed with a recess. The bead heel 35 includes a heel R portion having an arc shape. The bead back surface includes a recess R portion having an arc shape. A radius of curvature of the recess R portion is equal to or larger than a radius of curvature.

Provided is a pneumatic tire. A carcass line when 10% of a regular internal pressure is applied is composed of a curved line (S) connecting arcs having different radii of curvature and curved to project outward in a tire width direction and a curved line (T) curved to project inward in the tire width direction. A radius of curvature (R.sub.i) at a point on the curved line (S) and a radius of curvature (R.sub.i+1) at an adjacent point satisfy |R.sub.i+1−R.sub.i|/|(R.sub.i+1+R.sub.i)/2|≤0.25. An inclination (θ.sub.S) and an inclination (θ.sub.T) at a connection point (Q) of the curved line (S) and the curved line (T) satisfy |θ.sub.S−θ.sub.T|≤8°. A ratio (Hβ/Hα) between a radial height (Hα) at a maximum outer diameter position of a carcass layer and a radial height (Hβ) at a tire maximum width position satisfies Hβ/Hα ≥0.58.

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.

Disclosed are a cable bead and a tire. The cable bead includes a core wire located at the middle position of the bead and at least one layer of outer winding wires wound around the core wire, each layer of outer winding wires being evenly wounded along the circumferential direction of the core wire, where the cross section of the outer winding wires is a flat surface having a major axis and a minor axis; the major axis is perpendicular to the radial direction of the cross section of the bead, and the minor axis is parallel to the radial direction of the cross section of the bead; the outer winding wires are in surface contact with the core wire; and when there are at least two layers of outer winding wires, a line contact is formed between the layers of outer winding wires.

The invention relates to a heavy-load vehicle comprising at least one axle unit, the or each axle unit having at least one wheel, each wheel having at least one tire, at least one tire being a tubeless radial tire. The tubeless radial tire has an outer diameter of less than 755 millimeters (mm), and is adapted and configured for an internal pressure of at least 10 bar. In some instances, when used as a single tire, the tubeless radial tire has a load-bearing capacity per millimeter section width at a speed of 60 kilometers per hour (km/h) of at least 11 kilograms (kg).

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 resin-covered cord including n number of individual cords, disposed so as to be mutually spaced apart from each other, a covering resin that covers the cords, and an adhesive resin that is disposed between the cords and the covering resin and that has a greater tensile elastic modulus than the covering resin. Equation (1) below is satisfied, in which A is a total value of a width direction dimension of a portion where the cords and the adhesive resin are disposed, and B is a maximum value of a thickness direction dimension.

B<(A/n) (n≥1)  Equation (1)

A pneumatic tire is provided. In a meridian cross-section, an external contour shape of the bead core is a polygon formed by common tangent lines of a plurality of circumferential portions of a bead wire, the external contour shape includes a single vertex located toward the outside in a tire radial direction, an internal angle formed by two sides sandwiching the vertex is an acute angle, a bottom side of the external contour shape is inclined with respect to the tire lateral direction by from 2° to 9°, and the carcass layer is bent and folded back along a circumference of the bead core in a bead portion, a folded back portion of the carcass layer from a position of an outer end of the bead core in the tire radial direction extends toward a sidewall portion in contact with a body portion.

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.

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.