A pneumatic tire is provided that can achieve performance that is equivalent to or higher than that of known tires while allowing weight reduction of bead cores by using, for the bead cores, a composite cord. A pneumatic tire includes annular bead cores (5) embedded in bead portions (3), and a carcass layer (4) locked on the bead cores (5). Each of the bead cores (5) includes a cable bead structure in which a composite cord (10) is spirally wound around an annular core body (20), the composite cord including a core wire (11) formed of carbon fibers and a plurality of siding wires (12) formed of glass fibers disposed around the core wire (11).

A tire comprises at least one bead having an axial width at the seat D comprises at least one main circumferential reinforcing element of which the radially innermost point is at a radial distance Z and at an axial distance Y from the radially innermost point of the bead, and such that Y/D is at least equal to 0.5 and Z/D is at most equal to 0.4. This same bead comprises at least one bead layer surrounding the bead filler rubber such that its axially outermost end is radially on the outside of the end of the carcass layer and it also comprises at least one additional circumferential reinforcing element, radially on the inside of the radially outermost point of the main circumferential reinforcing element.

A tire comprises at least one bead having an axial width at the seat D comprises at least one main circumferential reinforcing element of which the radially innermost point is at a radial distance Z and at an axial distance Y from the radially innermost point of the bead, and such that Y/D is at least equal to 0.5 and Z/D is at most equal to 0.4. This same bead comprises at least one bead layer surrounding the bead filler rubber such that its axially outermost end is radially on the outside of the end of the carcass layer and it also comprises at least one additional circumferential reinforcing element, radially on the inside of the radially outermost point of the main circumferential reinforcing element.

A method of building a tire having no ply turnup is described. The method includes the steps of applying an inner liner and chafer onto a tire building drum; radially expanding the center portion of the drum and applying a first column bead, applying a layer of ply followed by the winding of a second column bead and the application of an apex, turning up the chafer and then inflating the carcass under low pressure below 150 mbars, applying the tread, applying the sidewall. A method of molding a green tire having a first and second bead area is described herein, wherein the method includes the steps of: inserting a tire clamping device inside a tire bladder and then inserting the tire clamping device and the bladder into the green tire, aligning the outer surfaces of the tire clamping device are in engagement with a respective bead area of the tire so that each tire bead area is clamped between a respective upper and lower mold ring and the tire clamping device during cure.

A run-flat tire comprises a tread portion, sidewall portions, bead portions, and a carcass ply extending between the bead portions. The sidewall portions are each provided therein with a sidewall reinforcing rubber layer having a crescent-shaped cross sectional shape and disposed on the axially inside of the carcass ply. The sidewall portions are each provided in the axially outer surface thereof with a rim protector which projects radially outward most on the radially outside of the radially inner edge of the sidewall reinforcing rubber layer. The bead portions are each provided therein with an axially inside core and an axially outside core between which each radially inner edge portion of the carcass ply is secured. When measured along a normal line drawn normally to the carcass ply from an apex of the rim protector, the thickness of the sidewall reinforcing rubber layer is in a range of from 29% to 35% of the thickness of the tire.

A run-flat tire comprises a tread portion, sidewall portions, bead portions, and a carcass ply extending between the bead portions. The sidewall portions are each provided therein with a sidewall reinforcing rubber layer having a crescent-shaped cross sectional shape and disposed on the axially inside of the carcass ply. The sidewall portions are each provided in the axially outer surface thereof with a rim protector which projects radially outward most on the radially outside of the radially inner edge of the sidewall reinforcing rubber layer. The bead portions are each provided therein with an axially inside core and an axially outside core between which each radially inner edge portion of the carcass ply is secured. When measured along a normal line drawn normally to the carcass ply from an apex of the rim protector, the thickness of the sidewall reinforcing rubber layer is in a range of from 29% to 35% of the thickness of the tire.

A run-flat tire has: a pair of bead cores; a carcass that straddles the pair of bead cores, and having end portions that are anchored on the bead cores; side reinforcing rubbers that are provided at tire side portions, and that extend in a tire radial direction along an inner surface of the carcass; a belt layer that is provided at an outer side, in a tire radial direction, of the carcass, and that is formed by covering a cord with resin; and a tread that is provided at an outer side, in a tire radial direction, of the belt layer.

A run-flat tire has: a pair of bead cores, each bead core formed by covering a wire with resin; a carcass that straddles the pair of bead cores, and having end portions that are anchored on the bead cores; side reinforcing rubbers that are provided at tire side portions, and that extend in a tire radial direction along an inner surface of the carcass; and a tread that is provided at an outer side, in a tire radial direction, of the carcass.

A pneumatic tire is provided that can achieve performance that is equivalent to or higher than that of known tires while allowing weight reduction of bead cores by using, for the bead cores, a composite cord. A pneumatic tire includes annular bead cores (5) embedded in bead portions (3), and a carcass layer (4) locked on the bead cores (5). Each of the bead cores (5) includes a cable bead structure in which a composite cord (10) is spirally wound around an annular core body (20), the composite cord including a core wire (11) formed of carbon fibers and a plurality of siding wires (12) formed of glass fibers disposed around the core wire (11).

A pneumatic tire is provided that can achieve performance that is equivalent to or higher than that of known tires while allowing weight reduction of bead cores by using, for the bead cores, a composite cord. A pneumatic tire includes annular bead cores (5) embedded in bead portions (3), and a carcass layer (4) locked on the bead cores (5). Each of the bead cores (5) includes a cable bead structure in which a composite cord (10) is spirally wound around an annular core body (20), the composite cord including a core wire (11) formed of carbon fibers and a plurality of siding wires (12) formed of glass fibers disposed around the core wire (11).