A pneumatic tire includes a carcass layer, a belt layer disposed outward of the carcass layer, a tread rubber disposed outward of the belt layer in a tire radial direction, sidewall rubbers disposed outward of the carcass layer in a tire width direction, and protectors disposed in regions from tire ground contact edges to maximum tire width positions and protruding from tire profiles. The protectors have a rubber hardness Hs_p in a range of 50≦Hs_p≦60, an elongation at break Eb_p in a range of 500%≦Eb_p≦700%, and an elastic modulus E_p in a range of 3.4 MPa≦E_p≦7.0 MPa.

A process for the manufacture of a tread band, wherein the blocks thereof comprise different portions having differing hysteresis losses. The process comprises a step for the extrusion of a preliminary tread band consisting of a first rubber compound and an injection step, wherein the preliminary tread band, once extruded, is subjected to the action of at least one injector arranged such as to penetrate into the layer of the preliminary tread band and to release a second rubber compound, which is distributed within the layer consisting of said first compound, maintaining exposed a surface that is suitable for defining a portion of the ground-contacting surface of the resulting tread band.

This disclosure provides a rubber composition that can realize excellent low heat generating properties without deteriorating other performance. The rubber composition contains a rubber component and a filler, where the rubber component contains a conjugated diene-based polymer modified with a modifier containing a compound represented by the formula (1).

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A pneumatic tire of the present disclosure includes, on a tread surface, circumferential main grooves extending in a tire circumferential direction and land portions defined between circumferential main grooves adjacent in a tire width direction among the circumferential main grooves or by the circumferential main grooves and tread edges. The land portions include widthwise grooves extending in the tire width direction and are divided into blocks by the widthwise grooves. At least one widthwise sipe extending in the tire width direction is included within the blocks. Hard rubber with a higher elastic modulus than that of tread rubber is disposed in a tire radial region including at least an opening to the tread surface of a wall defining the widthwise sipe. Microfabrication is applied in a region of the tread surface surrounding at least a portion of the opening of the widthwise sipe to the tread surface.

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 modified conjugated diene rubber having a modifying structure derived from a siloxane compound at at least one terminal of a polymer chain containing conjugated diene monomer unit and a monomer unit of a vinyl compound having a functional group interactive with silica.

In a tire, a tread includes a cap layer, an intermediate layer formed such that a loss tangent of the intermediate layer at 30° C. is less than a loss tangent of the cap layer at 30° C., and a base layer formed such that a loss tangent of the base layer at 30° C. is less than the loss tangent of the intermediate layer at 30° C. The intermediate layer is disposed outwardly of the base layer and the cap layer is disposed outwardly of the intermediate layer, in the radial direction. An outer end of the intermediate layer is disposed outwardly of an outer end of the base layer and an outer end of the cap layer is disposed inwardly of the outer end of the intermediate layer, in the axial direction. A difference between an axial width of the cap layer and an axial width of the base layer is not less than −10 mm and not greater than 10 mm.

The tread has a contact face that is provided with at least one circumferential groove and a transverse grooves opening to the contact face and delimiting contact elements. The tread has a center region and shoulder regions and is provided with at least one compressive contact element among the contact elements. A volumetric void ratio of the compressive contact element in a unit region surrounded by a center of the at least one circumferential groove and a center of the transverse grooves delimiting the compressive contact element is at least equal to 25%. An aspect ratio, which is defined as a ratio of a surface of the compressive contact element supposed to contact with ground divided by a sum of a surface area of the compressive contact element touching with air other than the surface of the compressive contact element supposed to contact with ground, is at most 70%.

In this pneumatic tire, a tan δ value T20 of a rubber member, which constitutes at least one of a bead filler, an undertread, a sidewall rubber, and a rim cushion rubber, at 20° C. and a tan δ value T60 of the rubber member at 60° C. satisfy 0.50≤T20/T60≤2.00 and T20≤0.22. Additionally, the tan δ value T20 of the rubber member at 20° C. is in a range T20≤0.15. Additionally, a tan δ value T20_sw of the sidewall rubber at 20° C. and a tan δ value T60_sw of the sidewall rubber at 60° C. satisfy 0.50≤T20_sw/T60_sw≤1.50 and T20_sw≤0.11.

Provided is a tire comprising a tread, wherein a ratio of a tire weight G (kg) to a maximum bad capacity W.sub.L (kg) of the tire (G/W.sub.L) is 0.0150 or less, wherein the tread has at least one rubber layer formed of a rubber composition comprising a rubber component and a reinforcing filler, and wherein a tan at 30° C. of the rubber composition is 0.15 or less, and a complex elastic modulus at 30° C. (E*.sub.30) of the rubber composition is 8.0 MPa or less.