In a tire 2 of the present invention, sidewalls 6 each include an outer layer 6a, and an inner layer 6b disposed inward of the outer layer 6a in the axial direction. A loss tangent of the inner layer 6b is less than a loss tangent of the outer layer 6a. When Hr represents a height, in the radial direction, from a bead base line BBL to an outer side end of a rim R, and Hi represents a height, in the radial direction, from the bead base line BBL to an inner side end 46 of the inner layer 6b, a ratio (Hi/Hr) of the height Hi to the height Hr is greater than or equal to 0.0 and not greater than 3.0.

In a tire 2 of the present invention, sidewalls 6 each include an outer layer 6a, and an inner layer 6b disposed inward of the outer layer 6a in the axial direction. A loss tangent of the inner layer 6b is less than a loss tangent of the outer layer 6a. When Hr represents a height, in the radial direction, from a bead base line BBL to an outer side end of a rim R, and Hi represents a height, in the radial direction, from the bead base line BBL to an inner side end 46 of the inner layer 6b, a ratio (Hi/Hr) of the height Hi to the height Hr is greater than or equal to 0.0 and not greater than 3.0.

A tire comprises a carcass ply extending between bead portions through a tread portion and sidewall portions, and turned up around a bead core in each of the bead portions from the inside to the outside in the tire axial direction so as to form a pair of turnup portions and a main portion therebetween. Each of the bead portions is provided with: a rubber bead apex disposed between the turnup portion and the main portion, and extending radially outwardly from the bead core in a tapered manner; a bead reinforcing rubber layer disposed axially outside the main portion; and an insulation rubber layer disposed between the main portion and the bead reinforcing rubber layer and having a hardness smaller than a hardness of the bead reinforcing rubber layer.

A tire comprises a carcass ply extending between bead portions through a tread portion and sidewall portions, and turned up around a bead core in each of the bead portions from the inside to the outside in the tire axial direction so as to form a pair of turnup portions and a main portion therebetween. Each of the bead portions is provided with: a rubber bead apex disposed between the turnup portion and the main portion, and extending radially outwardly from the bead core in a tapered manner; a bead reinforcing rubber layer disposed axially outside the main portion; and an insulation rubber layer disposed between the main portion and the bead reinforcing rubber layer and having a hardness smaller than a hardness of the bead reinforcing rubber layer.

A heavy-duty pneumatic tire includes a section width being equal to or less than 335 mm, an aspect ratio being equal to or less than 55%, and a toroidal carcass extending between axially spaced bead portions through a tread portion and sidewall portions. The carcass includes a carcass ply which includes a main portion and a turn-up portion turned up around a bead core of each bead portion. A belt layer is disposed radially outward of the carcass in the tread portion, wherein a radially outer end of the turn-up portion is located between the main portion and the belt layer in the tread portion. A sheeted rubber layer is disposed between the main portion and the turn-up portions in each sidewall portion.

A pneumatic tire comprises a carcass ply extending between bead portions through a tread portion and sidewall portions, and turned up around a bead core from the inside to the outside of the tire in each of the bead portions, so as to form a pair of turnup portions and a main portion therebetween. In each the bead portion, a first apex rubber and a second apex rubber are disposed. The first apex rubber is disposed between the turnup portion and the main portion. The second apex rubber is disposed axially outside the turnup portion. A complex elastic modulus b of the second apex rubber is larger than that of the first apex rubber. The cross-sectional width Wt in mm of the tire and the outer diameter Dt in mm of the tire satisfy the following conditions Dt=<59.078×Wt.sup.0.498 and Dt>=59.078×Wt.sup.0.460.

A pneumatic tire comprises a carcass ply extending between bead portions through a tread portion and sidewall portions, and turned up around a bead core from the inside to the outside of the tire in each of the bead portions, so as to form a pair of turnup portions and a main portion therebetween. In each the bead portion, a first apex rubber and a second apex rubber are disposed. The first apex rubber is disposed between the turnup portion and the main portion. The second apex rubber is disposed axially outside the turnup portion. A complex elastic modulus b of the second apex rubber is larger than that of the first apex rubber. The cross-sectional width Wt in mm of the tire and the outer diameter Dt in mm of the tire satisfy the following conditions Dt=<59.078×Wt.sup.0.498 and Dt>=59.078×Wt.sup.0.460.

To improve durability performance and rolling resistance performance in a well-balanced manner. It is a tire for heavy loads including a carcass ply (6A). A sidewall rubber (3G) includes an inside rubber part (15) on the carcass (6) side, and an outside rubber part (16) disposed on the outside thereof and forming a tire outer surface. The inside rubber part (15) has a loss tangent tan δ1 less than the outside rubber part (16), and their difference is 0.010 to 0.035. The inside rubber part (15) has a complex elastic modulus less than the outside rubber part (16), their difference is 0.5 to 1.4 (MPa). The outer end (15s) in the tire radial direction of the inside rubber part (15) contacts with the outer surface (2h) in the tire axial direction of the tread rubber (2G), and the inner end (15u) in the tire radial direction is disposed radially inside the outer end (6e) in the tire radial direction of the turned up portion (6b) of the carcass ply (6A).

A pneumatic tire, comprising at least sidewall portions and rim guards each provided at the corresponding sidewall portion, wherein: in a cross section in the width direction of the tire assembled with a prescribed rim, an outer contour line, of the rim guard, situated on the outer side in the tire radial direction than the radially outermost peak of the rim guard has an arcuate configuration of which the center of curvature is located on the external side of the tire; radius of curvature R of the outer contour line is in the range of 5 mm≦R≦40 mm; and provided that H represents a distance in the tire radial direction measured from the radially innermost peak to the outermost position in the tire radial direction of a rim flange, 2 mm≦H≦40 mm.

The bead portion of the pneumatic tire includes a bead structure having a bead core composed of bead cords, and an annular plate which is annular and extends to the tire circumferential direction and is formed of a resin material. The elastic modulus of the annular plate varies in tire radial direction.