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.

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 includes a tread portion, two axially spaced sidewall portions extending radially inwardly from the tread portion, at least one of the sidewall portions being provided with a side protector that protrudes axially outwardly and having an inner end located radially outwardly of a tyre-maximum-width position, and two axially spaced bead portions connected to radially inward of the respective sidewall portions. Each bead portion includes a bead apex rubber having an outer end in the tyre radial direction being located radially inwardly of the tyre-maximum-width position. A radial length of a tyre inner region from a bead baseline to the outer end of each bead apex rubber is in a range of from 0.8 to 1.2 times a radial length of a tyre outer region from a radially outermost position of the tread portion to the inner end of the side protector.

A pneumatic tyre includes a tread portion, two axially spaced sidewall portions extending radially inwardly from the tread portion, at least one of the sidewall portions being provided with a side protector that protrudes axially outwardly and having an inner end located radially outwardly of a tyre-maximum-width position, and two axially spaced bead portions connected to radially inward of the respective sidewall portions. Each bead portion includes a bead apex rubber having an outer end in the tyre radial direction being located radially inwardly of the tyre-maximum-width position. A radial length of a tyre inner region from a bead baseline to the outer end of each bead apex rubber is in a range of from 0.8 to 1.2 times a radial length of a tyre outer region from a radially outermost position of the tread portion to the inner end of the side protector.

Disclosed is a tubeless tire having a reinforced bead portion capable of reducing the stress applied to a portion contacting a rim flange and to an edge of a carcass. The tubeless tire includes a carcass turned up around a bead core, a bead filler filled in a space above the bead core surrounded by the carcass, a steel chafer disposed to contact an outer surface of the carcass, and a first reinforcing rubber layer provided between the bead core and the carcass in order to prevent a turnup portion of the carcass from being pulled downwards, the first reinforcing rubber layer being located around a portion of the bead core that is oriented toward a rim flange. The bead portion is improved in durability under a high- pneumatic-pressure condition by reducing the stress applied to interfaces of the edge of the carcass, the steel chafer and the nylon chafer.

A pneumatic tire includes a tread, sidewalls extending from edges of the tread, clinches extending from the edges of the sidewall, beads positioned on axially inner side of the clinches, a carcass bridging the beads along inner side of the tread and sidewalls, and load support layers positioned on axially inner side of the carcass such that the layers are positioned between the tread and beads. Each bead includes core and main apex, the core has radially outer side surface facing radially outward, the carcass includes carcass ply turned up around the core from inner side toward outer side in axial direction of the tire such that the main portion and turn-up portion are formed in the ply, the turn-up portion has core laminating portion laminated on the radially outer side surface of the core, and the apex is extending radially outward from radially outer side of the laminating portion.

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.

In a pneumatic tire (1) that achieves both ride comfort and steering stability at a high level, a bead core (5) has a ratio of the maximum width of the core to the height of the core of 0.8 or less in a cross-section in the tire width direction. A cord (9) is provided in at least one part from a bead portion (2) to a sidewall portion (3) at an angle of 0 to 10° with respect to the circumferential direction. The cord (9) has an inflection point in a stress-strain curve, with a low elastic modulus in a low-strain region at or below the inflection point, and a high elastic modulus in a high-strain region above the inflection point.

In the tire 2, fillers 10 are layered over clinches 8 in portions outward of a carcass 14 in the axial direction. A carcass ply 50 is turned up around cores 44. Turned-up portions 50a are disposed between the fillers 10 and apexes 46. Each clinch 8 has a maximum thickness Tcx that is measured along a line normal to an inner surface, in the axial direction, of the clinch 8. A ratio of a thickness Tf1 of the filler 10 to a sum of the thickness Tf1 and the thickness Tcx is greater than or equal to 0.1 and not greater than 0.6. A percentage of a complex elastic modulus E*f of the filler 10 relative to a complex elastic modulus E*a of the apex 46 is greater than or equal to 70% and not greater than 125%.

In the tire 2, fillers 10 are layered over clinches 8 in portions outward of a carcass 14 in the axial direction. A carcass ply 50 is turned up around cores 44. Turned-up portions 50a are disposed between the fillers 10 and apexes 46. Each clinch 8 has a maximum thickness Tcx that is measured along a line normal to an inner surface, in the axial direction, of the clinch 8. A ratio of a thickness Tf1 of the filler 10 to a sum of the thickness Tf1 and the thickness Tcx is greater than or equal to 0.1 and not greater than 0.6. A percentage of a complex elastic modulus E*f of the filler 10 relative to a complex elastic modulus E*a of the apex 46 is greater than or equal to 70% and not greater than 125%.