Each of at least two layers of a carcass reinforcement has a breaking force per unit width higher than 2250 daN/dm. The minimum strength per unit width, measured for an elongation of less than 10%, of a second layer of carcass reinforcement is strictly greater than a value equal to 20% of the minimum strength per unit width, measured for an elongation of less than 10%, of a first layer of carcass reinforcement. The reinforcing elements of the two layers of carcass reinforcement have a thread count of less than 750 tex. The elongation of the reinforcing elements of the second layer of carcass reinforcement is greater than 4% under a force of 20 daN, and the secant elastic modulus values under tension at 10% elongation, Mt, Mj, satisfy the relationship Mt/Mj≧1.

In the tire 2, fillers 10 are layered over clinches 8 in portions outward of a carcass 14 in the axial direction. A carcass ply 50 is turned up around cores 44. Turned-up portions 50a are disposed between the fillers 10 and apexes 46. Each clinch 8 has a maximum thickness Tcx that is measured along a line normal to an inner surface, in the axial direction, of the clinch 8. A ratio of a thickness Tf1 of the filler 10 to a sum of the thickness Tf1 and the thickness Tcx is greater than or equal to 0.1 and not greater than 0.6. A percentage of a complex elastic modulus E*f of the filler 10 relative to a complex elastic modulus E*a of the apex 46 is greater than or equal to 70% and not greater than 125%.

A run-flat tire includes a side reinforcing rubber layer, a first bead filler on an inner side of a carcass turned-up portion in a width direction, and a second bead filler on an outer side of the carcass turned-up portion in the width direction. A first bead filler height is 30% or less of a tire cross-sectional height SH. A second bead filler height is 50% or greater of the height SH. A cross-sectional area of the second bead filler is from 150% to 400% of a cross-sectional area of the first bead filler. A relationship (0.16×SH×LI−1100)≤S.sub.ALL≤(0.16×SH×LI−800) is satisfied, where S.sub.ALL represents a sum of cross-sectional areas of the side reinforcing rubber layer and the first and second bead fillers, and LI represents a load index.

A pneumatic tire having a tread, a sidewall, a bead portion having a bead core, a bead reinforcing layer reinforcing the bead portion, and a carcass ply moored on a bead core of the bead portion, wherein the bead reinforcing layer and adjacent members adjacent to the bead reinforcing layer are each composed of a rubber composition containing an amine type antioxidant, 0.3 to 8 parts by mass of the amine type antioxidant is contained in the bead reinforcing layer based on 100 parts by mass of the rubber component, and the adjacent member adjacent to the bead reinforcing layer and the bead reinforcing layer satisfy the following formula:
2≤B/A≤8
A: Content (wt %) of amine type antioxidant in bead reinforcing layer.
B: Content (wt %) of amine type antioxidant in the adjacent member.

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. The inner side end, in the radial direction, of the inner layer 6a extends to a region between a bead 10 and a chafer 8. When Po represents a contact point, on an outer surface of the tire 2, at which the outer layer 6a and the chafer 8 contact with each other, an inner side end, in the radial direction, of the outer layer 6a is equal to the contact point Po. In the radial direction, an outer side end 44 of the chafer 8 is disposed outward of the contact point Po. In the radial direction, an inner side end 46 of the inner layer 6b is disposed inward of the contact point Po.

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.

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 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 12 mm, a complex modulus of the first reinforcing rubber layer is from 6 MPa to 10 MPa, an elongation at break of the first reinforcing rubber layer is from 300% to 450%, a complex modulus of the second reinforcing rubber layer is from 10 MPa to 15 MPa, and a complex modulus of a shock absorbing rubber layer is from 2 MPa to 6 MPa.

In a pneumatic tire, a bead filler is on an outer circumference of a bead core, a carcass turned up end is inward of an outer diameter side end of the bead filler, the carcass end is spaced from a carcass body, a steel reinforcement is in each bead, a sidewall rubber extends from the sidewall to the bead, and a support layer is between the bead filler and the sidewall rubber to cover the carcass end and an end of the steel reinforcement, the support layer extending toward an outer diameter side and contacting the carcass body on an outer diameter side of the bead filler outer diameter side end, and a 100% modulus of the support layer is at least 1.5 times that of the bead filler, and the sidewall rubber, the bead filler and the sidewall rubber being adjacent to the support layer.