A tire (1) in which at least one of the said tread pattern blocks (51) comprises a circumferential reinforcing element (52) positioned axially on the inside relative to the said at least one groove (71) when working from the outside towards the inside and axially close to the said circumferential groove, the circumferential reinforcing element (52) is made of a rubber compound having a dynamic shear modulus G* at least twice as high as the dynamic shear modulus G* of the rubber compound of the rest of the blocks of the tread, the circumferential reinforcing element (52) extends radially from the radially exterior surface of the said crown reinforcement (6) towards the surface of the said tread with an axial width which decreases progressively with increasing radial proximity to the outside, and in which the said circumferential reinforcing element (52) partially forms the axially internal lateral face (7i) of the said at least one of the said tread pattern blocks (51).

Described are articles including treads and/or other tire components that are formed at least in part by rubber compositions having solid agglomerated material comprising disaggregated carbon nanotubes. Such rubber compositions include a diene rubber component and a solid agglomerated material comprising disaggregated carbon nanotubes that consist of a continuous network of carbon nanotubes that contains 1) voids and 2) aggregates of carbon nanotubes having a mean size d.sub.50 of less than 5 μm, the voids and the aggregates together in an amount that is less than 60% of a predetermined surface area, as determined by electron microscopy imagery analysis, the remainder being the disaggregated carbon nanotubes in the continuous network that do not comprise a clearly defined shape.

Provided is a tire for a motorcycle having an improved turning stability on wet road surface, the tire comprises a tread composed of a rubber composition, which comes into contact with a road surface, wherein Hs being a rubber hardness and M300 being a tensile stress (MPa) at 300% elongation of the rubber composition of the tread satisfy Equations 1, 2, and 3:
60≤Hs≤80,  Equation 1:
2≤M300≤12, and  Equation 2:
(M300−2)/(Hs−60)≤0.75.  Equation 3:

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 composition for seeded polymerization includes: a seed copolymer which has a compound having dithioate, a mercaptan compound, a first aromatic vinyl monomer, and a first conjugated diene monomer, and has an average particle diameter of 10-30 nm; a second aromatic vinyl monomer; and a second conjugated diene monomer.

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.

In a tire, an inclination angle of a cord included in a second belt layer with respect to a tire width direction is defined as a positive inclination angle in a tire see-through plan view, an intersection point between a perpendicular line drawn from an end portion of a belt layer having a maximum belt width in the tire width direction to a carcass and a cord of an outermost carcass layer in a tire radial direction is defined as a first reference point in a tire meridian cross-sectional view, and an inclination angle of the cord with respect to the tire width direction at the first reference point is −3° or more in the tire see-through plan view.

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 conjugated diene-based rubber including a polymer block (A) containing isoprene monomer unit as the main component and a polymer block (B) containing 1,3-butadiene monomer unit as the main component, wherein at least one of the polymer block (A) and the polymer block (B) contains a unit of a vinyl compound having a functional group interactive with silica, the polymer block (A) has a weight average molecular weight (Mw) in the range of 1,000 to 30,000, and the entire conjugated diene-based rubber has a weight average molecular weight (Mw) in the range of 50,000 to 5,000,000.

There is provided a rubber composition which can provide a tire having an excellent balance of the breaking properties, the rolling resistance performance (low fuel consumption) and the wet grip performance. The rubber composition includes 100 parts by mass of a diene rubber, and 1 to 100 parts by mass of fine particles (A) having a glass transition point of −70° C. to 0° C. and composed of a polymer comprising constituent units of at least one monofunctional monomer. The fine particles (A) have a crosslinked structure crosslinked by at least one polyfunctional monomer having a polysulfide bond in which at least two successive sulfur atoms are bonded together.