A tire for a two-wheeled motorized vehicle includes a tread joined by two sidewalls to two beads, the tread having first and second elastomer compositions, crown reinforcement, radially inside tread having a crown layer having mutually parallel circumferential reinforcers forming an angle at most equal to 5° to the circumferential direction, a carcass reinforcement, radially inside crown reinforcement, having turnup. Carcass reinforcement includes mutually parallel reinforcers, and wrapped, in each bead, from the inside to the outside of the tire, about bead wire in order to form turnup having free end E.sub.2. Carcass reinforcement includes crown portion and lateral portion, crown portion extending axially between first and second ends E.sub.2, E′.sub.2, E.sub.2 and E′.sub.2 being symmetric to equatorial plane P of the tire, lateral portion extending symmetrically to equatorial plane P radially towards the inside, from radially outermost end E.sub.2 to fourth end E.sub.4 disposed at the bead wire.

A tire has a tread 5 which includes grooves 7, the side faces 72 of which are undercut, and includes at least one circumferential reinforcing element 8-1 arranged axially relative to said undercut side face 72 at a distance “d” of between 0 and 15% of the axial width L51 of the tread block 51, at least extending radially from the inside towards the outside from a radial level situated above the wear limit level and to a radial height equal to 5% of the thickness “p” of the tread.

A motorcycle tyre (1) is described comprising an equatorial plane (X-X) and a tread band (8) comprising a radially inner portion (13) and a radially outer portion (11) respectively comprising a first and a second vulcanized elastomeric material obtained by vulcanizing respective elastomeric materials comprising 100 phr of at least one elastomeric diene polymer, from 30 to 130 phr of at least one reinforcing filler comprising an amount greater than 75% or, respectively, equal to or greater than 80% of a white filler. In the tyre (1) the ratio R1 between the dynamic elastic modulus (E′) and the tandelta measured at a frequency of 10 Hz and at 70° C. of the first vulcanized elastomeric material is comprised between 27 and 35, whereas the ratio R2 between the dynamic elastic modulus (E′) and the tandelta measured at a frequency of 10 Hz and at 70° C. of the second vulcanized elastomeric material is comprised between 15 and 30, the ratio R1/R2 being greater than or equal to 1.1.

A heavy duty pneumatic tire in which occurrence of uneven wear is inhibited is provided. In the tire, each shoulder land portion includes a groove wall portion forming a wall of a shoulder circumferential groove, and a cap portion located outward of the groove wall portion in an axial direction. A wear resistance index of the groove wall portion is lower than a wear resistance index of the cap portion. A ratio of a distance in the axial direction from an outer edge of the shoulder circumferential groove to a boundary between the groove wall portion and the cap portion on an outer surface of the shoulder land portion, to a width in the axial direction of the shoulder land portion, is not less than 20% and not greater than 30%.

A tire includes a tread portion including a first cap rubber layer forming a ground contact surface and having a loss tangent tan δ1, and a second cap rubber layer disposed inwardly in a tire radial direction of the first cap rubber layer and having a loss tangent tan δ2, the loss tangent tan δ2 being greater than the loss tangent tan δ1. The tread portion is provided with a plurality of sipes opening to the ground contact surface, The plurality of sipes, at least partially, extends inwardly in a tire radial direction from the ground contact surface to a. location beyond a boundary between the first cap rubber layer and the second cap rubber layer, and a maximum length L2 of the plurality of sipes in the second cap rubber layer is smaller than a length L1 of the plurality of sipes at the ground contact surface.

A tire for a vehicle comprises a tread (2), of which the central part of the tread (2) comprises at least two rubber compounds (221, 222), making up at least 90% of its volume. The first compound (221) is radially on the outside of the second compound (222) and makes up at least 40% and at most 60% of the volume of the central part. The second rubber compound (222) has a Shore hardness DS2 at least equal to 5 plus the Shore hardness DS1 of the first compound (221) and dynamic losses at a temperature of 0° C. and 23° C. that are at least equal to those of the first rubber compound (221). The axially outer parts of the tread are made up of a third compound (223) capable of touching the ground, having a stiffness and a hysteresis that are lower than those of the first compound.

A motorcycle tire comprises a carcass having a bias structure, a band comprising a jointiess ply, and a tread rubber disposed on the radially outside of the band. The loss tangent of the tread rubber at a temperature of 0 deg C. is larger in a tread crown region than in tread shoulder regions. The carcass comprises an outer carcass ply of carcass cords. The angles of the carcass cords with respect to the tire circumferential direction are smaller in the tread crown region than in the tread shoulder regions.

In the tread of the tire, the average modulus value in a center region including the equatorial plane of the tire is higher than the average modulus value in shoulder regions adjacent to edges of the tread, and in the shoulder regions, the modulus value is higher in a surface layer of the tread than in a portion other than the surface layer.

A radial tire (10), with the sidewalls thereof (20), and the tread thereof (30) arranged for minimizing the temperature of the tire while guaranteeing its electrical conductivity. The tread (30) comprises two wings (311, 312) and a central portion (32). These components rest on a base layer (33) radially on the inside of the tread (30). The base layer (33) contains a lateral portion (331, 332) partly in contact with a tread wing (311, 312). This structure of the crown of the tire, in contact with the carcass reinforcement makes it possible to constitute a preferential conductive pathway of the electric charges between the rim and the ground when the tire is mounted on its rim and flattened on the ground.

A motorcycle tire includes a tread rubber that includes a base rubber layer and a cap rubber layer disposed outward in the tire radial direction of the base rubber layer to form a ground contact surface. The cap rubber layer includes a crown cap portion disposed in a middle region in the tire axial direction of a tread portion and a pair of shoulder cap portions disposed in both sides in the tire axial direction of the crown cap portion. The crown cap portion has a loss tangent tan δc, the shoulder cap portions have a loss tangent tan δs, and the base rubber layer has a loss tangent tan δb, wherein the loss tangents tan δc, tan δs and tan δb satisfy the following equation (1): tan δc<tan δs≤tan δb . . . (1).