Provided is a heavy-duty pneumatic tire in which not only occurrence of a damage of CBU but also occurrence of pulling-out of a carcass ply can be inhibited, and which has excellent durability. In the tire, beads each include a cover enclosing at least a part of a core. The cover is located, between the core and the carcass ply, in a portion at which the carcass ply encloses the core. The cover is composed of one cover ply including a large number of aligned cover cords and a cover topping rubber covering the cover cords. A ratio of a distance between the cover cords to an outer diameter of a carcass cord is not lower than 0.35 and not higher than 0.85. A difference between a hardness of the cover topping rubber and a hardness of a carcass topping rubber is not less than −5 and not greater than 5.

A tire includes a carcass ply extending from one bead structure to another bead structure. Each bead structure includes a plurality of circumferentially wound sheath layers surrounding a bead core with a triangular cross-section. The cross-section has two radially inner vertices and a radially outer vertex. The radially outer vertex and one of the radially inner vertices are an angular amount radially offset from a directly radial direction of the tire.

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.

A pneumatic tire having a bead filler molded over a bead bundle to form an over-molded bead. The bead bundle may include at least one bead wire. The bead bundle may be over-molded with the bead filler, forming an over-molded bead. The over-molded bead may be formed into a variety of shapes and may be constructed from a variety of materials.

A heavy truck tire is provided that includes a tread and a casing. The casing has a bead with a bead core having padding gum and a rod with a perimeter. A contention armature surrounds the bead core and has an overlap, a majority of which is located outward in the radial direction from the rod. The padding gum is arranged in relation to the rod such that an outer area, inner area, and an axially outer area of the padding gum have areas that are greater than or equal to 20% of the area of the perimeter of the rod. An axially inner area of the padding gum is greater than or equal to 10% of the area of the perimeter of the rod.

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.

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°.

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/Mj≧1.

Provided is a pneumatic tire having laminated reinforcement layers with organic fiber over a polygonal cross-section bead core, and in the layer, a rubber-coated organic fiber cord is tilted to the center line of the bead core in a transverse section and is spirally coiled, in which each organic fiber cord in an inner and outer adjacent reinforcement layers over the bead core extends such that an organic fiber cord in the inner reinforcement layer and an organic fiber cord in the outer reinforcement layer intersect each other relative to the center line of the bead core in the transverse section, in which in the inner reinforcement layer, the cord is coiled with space at least partially in a tire circumferential direction such that the cord does not overlap in the tire circumferential direction, and the outer reinforcement layer is arranged to cover at least a part of the space.

A tire includes a circular tire frame member formed from a frame-resin material and a covered cord member. The covered cord member includes a reinforcing cord provided in the tire frame member and extending along a tire circumferential direction, a covering-resin layer formed from a covering-resin material, covering the reinforcing cord, and bonded to the tire frame member, and a bonding-resin layer. The bonding-resin layer is formed from a bonding-resin material having an elastic modulus higher than that of the covering-resin material, is interposed between the reinforcing cord and the covering-resin layer, bonds the reinforcing cord and the covering-resin layer together, and has a layer thickness thinner than a layer thickness of the covering-resin layer.