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.

A heavy goods vehicle tire has a radial carcass reinforcement, made up of a single layer of metal reinforcing elements anchored in each of the beads by a turn-up around a bead wire. The turn-up of the carcass reinforcement layer and the main part of the carcass reinforcement layer are coupled, and a radiofrequency communication module is placed in the coupling region at the interface between the turn-up of the carcass reinforcement layer and axially outwardly adjacent layer of rubber compound.

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 tire manufacturing method includes making a master batch, using the master batch to make a rubber composition, and making a green tire. The master batch is made wherein a carbon-black-containing pre-coagulation rubber latex is coagulated to obtain a coagulum; a compound according to Formula (I) is added to the water-containing coagulum; ##STR00001##
wherein R.sup.1 and R.sup.2 each indicates a hydrogen atom, an alkyl group having 1 to 20 carbons, an alkenyl group having 1 to 20 carbons, or an alkynyl group having 1 to 20 carbons, R.sup.1 and R.sup.2 may be the same or different, and M.sup.+ indicates sodium ion, potassium ion, or lithium ion; and the compound according to Formula (I) is dispersed within the coagulum. The green tire is provided with unvulcanized rubber sheeting made up of the rubber composition, chafer(s), carcass ply or plies, and bead filler(s).

A tire is equipped with a radiofrequency communication module with a carcass reinforcement comprising two carcass plies such that the communication module is positioned in the bead axially on the outside of and against the second carcass ply.

A tire includes tire frame members including bead cores, a bead filler, an inner liner, side-wall rubber and cushion rubber; and an electronic unit provided at an interface of tire frame members, the tire further including: a carcass ply which extends from one bead core to another bead core and includes a rubber-coated reinforcement cord, a belt disposed on the outer side in the tire-radial direction of the carcass ply, in which the cushion rubber is disposed at an end of the carcass ply or at an end of the belt, in which the side-wall rubber is disposed on an outer side in a tire-width direction of the cushion rubber, and in which the electronic unit is disposed between the cushion rubber, and the bead filler or the side-wall rubber.

The pneumatic tire comprises a pair of bead cores, a pair of bead fillers disposed outward of the pair of bead cores in a tire radial direction, a carcass layer disposed folded around the bead cores and the bead fillers, and a steel chafer including an arranged plurality of steel cords, the steel chafer being disposed between the carcass layer and a rim engaging surface. A height Hs of an outer end portion of the steel chafer located outward of the bead fillers in a tire width direction and a rim flange height Hf have the relationship: 0.5Hs/Hf1.0, where the height is measured from a measuring position of a rim diameter.

In a pneumatic tire including a side reinforcing layer, the maximum width W0of a bead core and the widths W1, W2 of the bead core at innermost and outermost sides in the radial direction, respectively, satisfy W1>W2 and W20.5W0. W0 is toward the inside of the center of the bead core in the radial direction. A carcass is folded and curved along the bead core, and a folded back portion of the carcass extends toward the sidewalls while contacting a body of the carcass. A rubber occupancy ratio in a region formed by the body and the folded back portion of the carcass is 0.1% to 15%. The cross-sectional area S2 of a filler toward the outside of the carcass in the lateral direction, the hardness H2 of the filler, the cross-sectional area S1of a side reinforcing layer and the hardness H1 of the side reinforcing layer satisfy 0.15(S2H2)/(S1H1)0.60.

Of layers configuring a bead core of a pneumatic tire, the width W0 of one of the layers including the greatest number of rows, the width W1, W2 of other of the layers located respectively innermost and outermost in the radial direction satisfy W1>W2 and W20.5W0. The position of width W0 is inward in the radial direction of the center of the bead core. A carcass is folded and curved along the bead core and extends toward sidewalls where a folded back portion of the carcass contacts a body of the carcass. A rubber occupancy ratio in a closed region formed by the body and the folded back portion is 0.1% to 15%. The cross-sectional area S2 and hardness H2 of a filler outward of the carcass in the lateral direction, and the cross-sectional area S1 and the hardness H1 of the side reinforcing layer satisfy 0.12(S2H2)/(S1H1)0.50.

In a pneumatic tire, a rubber occupancy ratio in a closed region is in a range of 15% or less. Bead cores have a predetermined wire arrangement structure formed by arranging wire cross sections of bead wires in a cross-sectional view in a tire meridian direction. A tangential contacts an innermost layer in a tire radial direction and the wire cross sections innermost and outermost in a tire lateral direction in the wire arrangement structure from a rim fitting surface side. Contact points of the tangent line are on the innermost and outermost wire cross sections. A gauge is in the tire lateral direction from the midpoint to the rim fitting surface. A rate of change of the gauge between before and after mounting on a rim is in a range from 10% or greater to 60% or less.