A tire having a radial carcass reinforcement, made up of a single layer of reinforcing elements anchored in each of the beads by being turned up around a bead wire, reinforced by a stiffener. In the sidewall of the tire, the profile of the outer surface of the tire is at a constant distance from the carcass reinforcement layer between the points F and A, and meets the outer surface of the bead at the point C, forming two successive circular arcs.

The invention provides a heavy-duty tire rubber composition excellent in wet grip performance and steering stability, and a tire tread, a bead filler, a tire belt and a heavy-duty tire which each partially include the composition. The heavy-duty tire rubber composition includes 100 parts by mass of a solid rubber (A), 0.1 to 50 parts by mass of a modified liquid diene rubber (B) having a functional group derived from a silane compound with a specific structure, and 20 to 200 parts by mass of a filler (C), the modified liquid diene rubber (B) satisfying the following (i) and (ii): (i) the weight average molecular weight (Mw) is not less than 1,000 and not more than 120,000, and (ii) the vinyl content is not less than 30 mol % and less than 70 mol %.

The invention provides a heavy-duty tire rubber composition excellent in wet grip performance and steering stability, and a tire tread, a bead filler, a tire belt and a heavy-duty tire which each partially include the composition. The heavy-duty tire rubber composition includes 100 parts by mass of a solid rubber (A), 0.1 to 50 parts by mass of a modified liquid diene rubber (B) having a functional group derived from a silane compound with a specific structure, and 20 to 200 parts by mass of a filler (C), the modified liquid diene rubber (B) satisfying the following (i) and (ii): (i) the weight average molecular weight (Mw) is not less than 1,000 and not more than 120,000, and (ii) the vinyl content is not less than 30 mol % and less than 70 mol %.

A chamber is provided that works as a peristaltic pump for the pressure correction in the tire, which is a part of the tire or of an ancillary structure placed between the rim and the tire bead and is connected with the tire internal space at one end and with the external environment at the other end. The chamber is in the shape of a curved hollow channel, where at least one enclosing wall is at least partially formed by at least a pair of surfaces coplanar with the longitudinal direction of the chamber. When the tire is mounted on the rim, the pair of surfaces are pressed together thus hermetically closing the chamber. When the chamber is closed during rotation of the wheel, the surfaces can slightly slide on one another taking internal wall tensions onto themselves thus decreasing the possibility of wall damage through ripping.

A chamber is provided that works as a peristaltic pump for the pressure correction in the tire, which is a part of the tire or of an ancillary structure placed between the rim and the tire bead and is connected with the tire internal space at one end and with the external environment at the other end. The chamber is in the shape of a curved hollow channel, where at least one enclosing wall is at least partially formed by at least a pair of surfaces coplanar with the longitudinal direction of the chamber. When the tire is mounted on the rim, the pair of surfaces are pressed together thus hermetically closing the chamber. When the chamber is closed during rotation of the wheel, the surfaces can slightly slide on one another taking internal wall tensions onto themselves thus decreasing the possibility of wall damage through ripping.

Provided is a pneumatic tire. A band-like sound absorptive member is fixed to the inner surface of a tread portion along the tire circumferential direction. An end portion in the tire width direction of the sound absorptive member is located on the outer side in the tire width direction with respect to a shoulder main groove located on the outermost side in the tire width direction. A width W1 of the sound absorptive member in the tire width direction and a tread development width TDW of the tread portion satisfy a relationship of 0.65≤(W1/TDW)≤0.90. The width W1 of the sound absorptive member and a belt width W2 of a first belt ply having the maximum width of a belt layer satisfy a relationship of 0.70≤(W1/W2)≤0.95.

In a pneumatic tire including a bead core, a first bead filler on an outer circumference of the bead core, a carcass turned up from an inner side to an outer side around the bead core and the first bead filler, and a second bead on an outer side of a turned up portion of the carcass, a height of an upper end of the first bead filler is 10%-30% of a cross-sectional height, a turned up end of the carcass is on a radially outer side of a maximum width position, an upper end of the second bead filler is between the upper end and the turned up end, the second bead filler has a shape tapered toward the radially outer side, and thicknesses G1 to G3 of the second bead filler at predetermined positions satisfy 0.5<G2/G1<0.8 and 0.4<G3/G1<0.6.

In a pneumatic tire including a bead core, a first bead filler on an outer circumference of the bead core, a carcass turned up from an inner side to an outer side around the bead core and the first bead filler, and a second bead on an outer side of a turned up portion of the carcass, a height of an upper end of the first bead filler is 10%-30% of a cross-sectional height, a turned up end of the carcass is on a radially outer side of a maximum width position, an upper end of the second bead filler is between the upper end and the turned up end, the second bead filler has a shape tapered toward the radially outer side, and thicknesses G1 to G3 of the second bead filler at predetermined positions satisfy 0.5<G2/G1<0.8 and 0.4<G3/G1<0.6.

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 comprises a carcass which comprises a carcass ply composed of a main portion extending between bead portions and a pair of turned-up portions turned-up around respective bead cores. The bead portion is provided with: a primary bead apex rubber disposed between the carcass-ply main portion and the carcass-ply turned-up portion; an insulation rubber layer extending radially outwardly through between the carcass-ply main portion and the carcass-ply turned-up portion; and a subsidiary bead apex rubber layer disposed on the axially outside of the carcass-ply turned-up portion. The radially outer edge of the insulation rubber layer is located radially outside the radially outer edge of the subsidiary bead apex rubber layer. The complex elastic modulus of the insulation rubber layer is equal to or greater than the complex elastic modulus of the topping rubber of the carcass ply.