A cord (50) comprises a single layer (52) of helically wound metal filamentary elements (54). The metal filamentary elements define an internal enclosure (58) of the cord of diameter Dv. Each metal filamentary element (54) has a diameter Df and a helix radius of curvature Rf. With Dv, Df and Rf being expressed in millimetres, the cord satisfies the following relationships: 9≤Rf/Df≤30 and 1.30≤Dv/Df≤2.10.

A tire pair includes a front tire 2 and a rear tire 52. The front tire 2 includes a pair of beads 18, a carcass 10 extending on and between a first bead 18 and a second bead 18, a tread 4 located outward of the carcass 10 in a radial direction, and a band 14 located between the tread 4 and the carcass 10 in the radial direction. The carcass 10 includes a large number of carcass cords 30 aligned with each other and each tilted relative to an equator plane. The band 14 includes a band cord 34 extending substantially in a circumferential direction. A ratio (Jf/Jr) of a bending stiffness Jf of the band cord 34 of the front tire 2 to a bending stiffness Jr of a band cord 84 of the rear tire 52 is not less than 0.0 and less than 0.7.

An outer diameter of a pneumatic tire 350 mm or more and 600 mm or less. As RW is defined by a rim width of a rim wheel assembled to the pneumatic tire and SW is defined by a tire width of the pneumatic tire, the relation of 0.78≤RW/SW≤0.99 is satisfied. A carcass has a carcass cord arranged along the tire width direction. The carcass cord is formed of a filament of steel. The outer diameter of the carcass cords is 0.7 mm or less, and a distance between adjacent carcass cords is 4.0 mm or less.

A tire comprises a tread portion provided with a band composed of at least one band cord wound spirally and circumferentially of the tire and embedded in the tread portion. When a band cord piece is taken out from the above-said at least one band cord embedded in the tread portion and measured for the length, a length Lb is equal to or smaller than a length La at least in a part of the tread portion, where the length Lb is measured at a first point of time after the band cord piece has been taken out, and the length La is measured at a second point of time after the first point of time.

The present invention provides a tire that uses an elastomer-metal cord composite, which composite is obtained by coating metal cords with an elastomer, each metal cord being composed of a bundle of metal filaments arranged without being twisted, and which composite is capable of highly improving the performance of the tire. The above-described tire is a tire (100) including a belt (105) which includes at least two belt layers (105a) and (105b). In this tire, the belt layers (105a) and (105b) are each obtained by coating metal cords (2) with an elastomer (3), each metal cord (2) being composed of a bundle of a plurality of metal filaments (1) arranged in a row without being twisted; the metal filaments (1) are shaped, and at least one pair of adjacent metal filaments (1) in the metal filaments (1) have different phases from each other; each of the belt layers (105a) and (105b) has a thickness of more than 0.30 mm and less than 1.00 mm; and the distance in the tire radial direction between the metal cords (2) in the two adjacent belt layers (105a) and (105b) is 0.10 mm or more and 1.20 mm or less, at the center of the tire.

Provided is a multi-twisted steel cord for reinforcing a rubber article, the steel cord having cord strength with a small loss as compared to the total strength of filaments constituting the cord and a high rubber penetration. The steel cord includes a plurality of twisted strands in a multi-twisted structure, each strand including a plurality of twisted filaments in two or more layers, in which at least some of the filaments have a tensile strength of 3,000 MPa or more, the steel cord satisfying a filament occupancy of 48% or more and less than 54%, a cord twist angle of 78° or more and less than 84°, an average crossing angle between adjacent filaments other than wrapping filaments of less than 17°, and a gap between adjacent sheath filaments constituting the strand of 0.065 mm or more.

A steel wire having a flat shape in a cross-section perpendicular to a longitudinal direction, wherein an outer shape of the cross-section includes a first straight portion, a second straight portion arranged opposite to the first straight portion, and a first curved portion and a second curved portion that connect the first straight portion to the second straight portion, wherein the first curved portion is arranged opposite to the second curved portion, and wherein a ratio of W1 to W2 is 75% or less, where W1 is an average value of a length of the first straight portion and a length of the second straight portion, and W2 is a maximum distance between the first curved portion and the second curved portion.

A plurality of belt layers 7 are superimposed in a radial direction. The belt layers 7 include a plurality of steel cords 10 arranged in parallel in a row and rubber 11. The steel cords 10 have a 1×4 structure in which four filaments 20 are twisted, and when a center-to-center distance between the steel cords 10 in at least two of the belt layers 7 adjacent in the radial direction is T, and an average diameter of virtual circumscribed circles of the steel cords 10 having the 1×4 structure is D, 1.25≤T/D≤2.25.

Provided are a steel cord and a single steel wire having excellent straightness quality for reinforcing tire and a method of manufacturing the steel cord and single steel wire. The steel cord and the single steel wire include a wire undergoing through a drawing process, a heating process performed in a state in which tension is applied to the wire, and a cooling process; and a winding portion on which the wire is wound, the winding portion having a diameter greater than a diameter of the wire, wherein, when an end of the wire that has been wound on the winding portion for six months to one year is fixed on a point and the wire is pulled down vertically to 400 mm, a distance between a first axis that is perpendicular to the point and an opposite end of the wire is 30 mm or less. The method of manufacturing the steel cord and single steel wire having excellent straightness quality for reinforcing tire includes: a wire preparing process, a heating process, a cooling process, and a winding process.

A rubber composition contains a rubber component, an organic phosphoric acid compound having at least one alkyl chain, a vulcanizing agent, and a vulcanization accelerator. A content of a cobalt-containing compound is 0.00 parts by mass or more and less than 0.01 parts by mass as converted to a cobalt amount per 100 parts by mass of the rubber component. A content of N,N-dicyclohexyl-2-benzothiazolylsulfenamide is 0.00 parts by mass or more and less than 0.08 parts by mass per 100 parts by mass of the rubber component. The rubber composition can be used to produce a rubber-metal composite excellent in heat-resistant adhesion between a vulcanized rubber and a metal.