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.

A pneumatic tire includes a pair of bead portion, a pair of bead cores, a carcass extending between the pair of bead cores, and a pair of bead apex rubbers. Each bead core includes a core inner surface on an inner side in the tire radial direction of the bead core. In a pre-assemble state, each core inner surface has an angle of 20 degrees plus/minus 2 degrees to the tire axial direction, and is inclined outwardly in the tire radial direction toward an outer side in the tire axial direction. The bead apex rubber includes a first rubber portion arranged so as to cover a circumference of the bead core and having a circular or substantially elliptical outline, and a second rubber portion tapering outwardly in the tire radial direction from the first rubber portion. The first rubber portion is greater in hardness than the second rubber portion.

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.

A pneumatic tire includes a pair of bead portion, a pair of bead cores, a carcass extending between the pair of bead cores, and a pair of bead apex rubbers. Each bead core includes a core inner surface on an inner side in the tire radial direction of the bead core. In a pre-assemble state, each core inner surface has an angle of 20 degrees plus/minus 2 degrees to the tire axial direction, and is inclined outwardly in the tire radial direction toward an outer side in the tire axial direction. The bead apex rubber includes a first rubber portion arranged so as to cover a circumference of the bead core and having a circular or substantially elliptical outline, and a second rubber portion tapering outwardly in the tire radial direction from the first rubber portion. The first rubber portion is greater in hardness than the second rubber portion.

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.

The outer diameter of the pneumatic tire is 350 mm or more and 600 mm or less, and the tire width is 125 mm or more and 255 mm or less. An aspect ratio of the pneumatic tire is 40% or more and 75% or less, a rim diameter of a rim wheel is 10 inches or more and 22 inches or less, and a rim width of the rim wheel is 3.8 inches or more and 8 inches or less. The pneumatic tire satisfies the relationship of 0.78≤RW/SW≤0.99 and 0.56≤RD/OD≤0.75. The carcass has a plurality of carcass cords arranged at intervals, the carcass cords are formed of prescribed organic fibers, and the breaking strength of the carcass cords is ≥2.2 kN/cm.

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 α with the axial direction in a radial sectional half-plane R, on N layers superposed on one another in the radial direction, wherein: α 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.

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 including: a pair of bead cores formed in a polygonal shape in cross-sectional view; a carcass toroidally straddling between the bead cores and folded back around the bead cores; and a wire chafer extending along the carcass so as to cover the carcass folded back around the bead cores from an inner side in a radial direction of a tire, in which, at a side on a tire inner circumference side of the bead core, the wire chafer is provided by being separated into an upper side wire chafer and a lower side wire chafer.