An insert rubber for improving aerodynamics of a tire and an installation method thereof, and provides an insert rubber for improving aerodynamics of a tire and an installation method thereof, in which, by eliminating a space which is located between a bead of a tire and a flange of a rim, airflow is prevented from being introduced between the bead and the flange while a vehicle travels, and the space between the bead and the flange is filled with the insert rubber, thereby preventing turbulence from being generated in the space between the bead and the flange.

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.

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.

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 pneumatic tire mountable on a 15° tapered specified rim includes a bead core, a carcass, a steel cord reinforcing layer, a bead rubber layer, and a first reinforcing rubber layer. A distance from a second line segment to a third line segment is from 4 mm to 8 mm; a side of an outer portion and a side of an inner portion of a bead base portion bend at an inflection point located in a range from 8 mm to 18 mm from the first intersection point; and an angle γ formed by an extension line drawn from the side of the outer portion inward in the tire radial direction and the side of the inner portion is from 4.5° to 14.5°.

A pneumatic tire mountable on a 15° tapered specified rim includes a bead core, a carcass, a steel cord reinforcing layer, a bead rubber layer, and a first reinforcing rubber layer. A distance from a second line segment to a third line segment is from 4 mm to 8 mm; a side of an outer portion and a side of an inner portion of a bead base portion bend at an inflection point located in a range from 8 mm to 18 mm from the first intersection point; and an angle γ formed by an extension line drawn from the side of the outer portion inward in the tire radial direction and the side of the inner portion is from 4.5° to 14.5°.

A pneumatic tire assembly includes: a tread portion including one or more traction features; a first sidewall portion coupled to the tread portion; and a first bead portion coupled to the first sidewall portion; wherein the first sidewall portion includes multiangle first tread traction features positioned proximate the tread portion.

A pneumatic tire assembly includes: a tread portion including one or more traction features; a first sidewall portion coupled to the tread portion; and a first bead portion coupled to the first sidewall portion; wherein the first sidewall portion includes multiangle first tread traction features positioned proximate the tread portion.

A motorcycle tire comprises a pair of bead portions each with a bead core therein and a bead bottom surface. In a non-rim assembled state in which the bead portions are held such that the axial distance between the axially outer surfaces of the bead portions matches the rim width of a regular rim, a conditional expression: 0.99 =< Dc/(Dr+2T) =< 1.00, is satisfied, wherein “Dc” is the inner diameter of the bead core at the axial center position of the bead core, “Dr” is the rim diameter of the regular rim, and “T” is the radial distance from the inner surface of the bead core to the bead bottom surface at the axial center position.

A motorcycle tire comprises a pair of bead portions each with a bead core therein and a bead bottom surface. In a non-rim assembled state in which the bead portions are held such that the axial distance between the axially outer surfaces of the bead portions matches the rim width of a regular rim, a conditional expression: 0.99 =< Dc/(Dr+2T) =< 1.00, is satisfied, wherein “Dc” is the inner diameter of the bead core at the axial center position of the bead core, “Dr” is the rim diameter of the regular rim, and “T” is the radial distance from the inner surface of the bead core to the bead bottom surface at the axial center position.