A method of manufacturing a pneumatic tire has a winding step of forming a rubber ribbon winding body constructing a tread rubber by spirally winding a rubber ribbon obtained by co-extruding a first rubber and a second rubber which are different in hardness. The first rubber is mainly arranged in a first area by making a cross sectional area ratio of the first rubber greater than that of the second rubber. The second rubber is mainly arranged in a second area by making the cross sectional area ratio of the first rubber smaller than that of the second rubber. The cross sectional area ratio of the first rubber becomes progressively smaller in a part of the first area as the second area approaches. The rubber ribbon retains an interface boundary between the first rubber and the second rubber to at least a part of the second area.

A tire comprises a tread portion 2. The tread portion 2 includes a tread ground contacting surface (2s) and at least one main groove 3 recessed from the tread ground contacting surface (2s) and extending continuously in a tire circumferential direction. The main groove 3 has a first groove wall 11. The first groove wall is provided with a recessed portion 15 recessed outwardly in a groove width direction from a groove edge of the main groove 3 on the tread ground contacting surface. The recessed portion 15 is formed of groove wall rubber 8 having a complex elastic modulus larger than that of base rubber 7 forming a main portion of the tread ground contacting surface (2s).

Tire comprising a tread (40) extending between an outboard axial edge (45) and an inboard axial edge (46), over a width L, in which the tread comprises at least 4 circumferential ribs (411-414) separated by grooves (421-423), in which the circumferential rib (411) adjacent to the outboard axial edge of the tread extends from the outboard axial edge over a width of at least 0.6.Math.L and comprises a portion (411a) with a width of at least 0.1.Math.L made from a first rubber composition and an axially adjacent second portion (411b) made from a second rubber composition, the first rubber composition having values for the elastic modulus at 300% deformation, the Shore A hardness and the complex modulus G* at 60 C. which are respectively comprised between 1.1 and 2.1 times, 0.95 times and 1.20 times, and 1.00 times and 2.10 times the corresponding values of the second rubber composition.

Airplane tire tread (2), having an axial width L, comprises a middle part (3) having an axial width L.sub.C at least equal to 50% and at most equal to 80% of L and composed of a middle rubber composition, and two lateral parts (41, 42), positioned axially on either side of the middle part (3), each having an axial width (L.sub.S1, L.sub.S2) between 10% and 25% of L and each composed of a lateral rubber composition. The middle rubber composition comprises at least 50 phr of a first diene elastomer, a reinforcing filler and a crosslinking system, which first diene elastomer comprises ethylene units and diene units comprising a carbon-carbon double bond, which units are distributed randomly within the first diene elastomer, the ethylene units representing at least 50 mol % of all the monomer units of the first diene elastomer.

A tire is provided with a tread that includes first and second sectors and grooves. The second sectors are formed of a rigid reinforcing compound. Each of the first and second sectors has a contact face intended to contact a road surface when the tire is in use. Each groove includes sidewalls and a bottom, and extends from an end of an adjacent contact face. A depth P of each groove is measured in a radial direction between its bottom and a position corresponding to a radial height of the adjacent contact face. At least one of the second sectors has a contact face that includes a recess having a depth p of less than 2 mm, as measured in a radial direction from a surface of the recess to a position corresponding to a radial height of an adjacent first sector.

The present invention relates to a pneumatic tire having a tread comprising a tread base layer and a tread cap. The tread cap comprises a first tread cap layer and a second tread cap layer of different polymeric compositions, the tread cap having a central cap zone Z.sub.C and two lateral cap zones Z.sub.L the lateral cap zones Z.sub.L being located axially adjacent to the central cap zone Z.sub.C and on axially opposite sides of the central cap zone Z.sub.C.

Tire comprising a tread which has at least one central rib (411-413) and two lateral ribs (421-422) which are separated by circumferential grooves (141-144), in which tire a first lateral rib (421) adjacent to the outer axial edge of the tread and at least one (and preferably each) of the central ribs have a first portion (4211, 4111, 4121, 4131) the axial width of which exceeds 2 % of the axial width of the relevant rib made and the depth of which is less than that of the relevant rib, from a rubber composition containing an elastomer and a reinforcing filler consisting predominantly of carbon black, and an axially adjacent second portion (4212, 4112, 4122, 4132) made of a rubber composition containing an elastomer and a reinforcing filler a minority proportion of which consists of carbon black, in which the rubber compositions that make up the second portion of the first lateral rib and the second portion of the central rib all have a tan 50 value which is higher than the tan 50 value of the rubber compositions that form the first portion of the first lateral rib and the first portion of the central rib, the tan 50 values being measured at a temperature of 0? C. and under a stress of 0.7 MPa.

A tire includes two beads, two sidewalls connected to the beads, and a crown. The crown includes a belt reinforcement, a tread, and a stiffening ply. The belt reinforcement has an axial width W. The tread includes tread pattern blocks and grooves having a groove bottom. The tread is made of a material that has a dynamic shear modulus G* of less than 1.25 MPa. The stiffening ply includes filamentary reinforcing elements that are rigid in terms of compression, and that are arranged under at least one of the grooves of the tread.

The present invention is directed to pneumatic tire having a tread comprising a tread base layer and an outer cap layer disposed radially outward of the base layer, the outer cap layer comprising an axially central zone and two lateral zones each disposed axially adjacent to the central zone; the central zone comprising a central zone composition and lateral zones each comprising a lateral zone composition; the central zone composition and the lateral zone composition each comprising, based on 100 parts by weight of elastomer (phr), from about 50 to about 90 phr of a solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) ranging from 65 C. to 55 C. and functionalized with an alkoxysilane group and at least one functional group selected from the group consisting of primary amines and thiols; from about 50 to about 10 phr of polybutadiene having a cis 1,4 content greater than 95 percent and a Tg ranging from 80 to 110 C.; from 100 to 180 phr of precipitated silica; and from 30 to 80 phr of a combination of a resin having a Tg of at least 30 C. and an oil wherein the weight ratio of the amount of silica to the total amount of resin and oil is less than 3; wherein the weight ratio of resin to oil in one of the central zone composition and lateral zone composition is greater than 2, and the weight ratio of resin to oil in the other of the central zone composition and lateral zone composition is less than 2.

Tire tread has a central rib (411-413) and two lateral ribs (421-422) which are separated by circumferential grooves (141-144). A first lateral rib (421) adjacent to the outer axial edge of the tread and a central rib have a first portion (4211, 4111, 4121, 4131) the axial width of which exceeds 20% of the axial width of the relevant rib made from a first rubber composition containing an elastomer and a reinforcing filler consisting predominantly of carbon black, and an axially adjacent second portion (4212, 4112, 4122, 4132) made of a second rubber composition containing an elastomer and a reinforcing filler a minority proportion of which consists of carbon black. The second rubber composition has a tan d0 value which is less than the tan d0 value of the first rubber composition, the tan d0 values being measured at a temperature of 0 C and under a stress of 0.7 MPa.