A run-flat tire includes a belt reinforcing layer outward of a belt layer in a tire radial direction and reinforcing rubber in sidewall portions. Where a center region is a region of a tread portion in which a center land portion corresponding to a land portion included in land portions in a tread portion and located closest to a tire equatorial plane is positioned, the belt reinforcing layer includes a center reinforcing portion in which more pieces of the belt reinforcing layer are layered at a position of the center region than at positions other than the position of the center region, and in the belt reinforcing layer, a width Wc of the center reinforcing portion in a tire lateral direction with respect to a thickness Gr of the side reinforcing rubber at a tire maximum width position is within a range of 0.5 Gr≤Wc≤2.0 Gr.

A tire having a tread comprising at least two radially superposed portions which comprise a radially external portion being made of a first rubber composition (FC), and a radially internal portion being made of a second rubber composition (SC); the tread comprising a plurality of tread pattern elements (1) delimited by cut-outs (3, 4); the tread pattern elements (1) respectively comprising at least one lateral face (13, 14, 15, 16) and a contact surface (2) intended to come into contact with the ground during rolling; the external portion of the tread pattern elements (1) being at least partially covered on at least one of the lateral face(s) (13, 14, 15, 16) with a layer of a third rubber composition (TC).

A heavy duty pneumatic tire 1 has provided in a buttress region 10 thereof a protrusion 11 extending in the tire circumferential direction. In a tire meridian cross-section, the maximum protrusion height h.sub.max of the protrusion 11 from an imaginary buttress surface J is 3.0 mm or greater and is in the range of 0.025-0.050 times a half tread width Wt. The cross-sectional area Sa of the protrusion 11 protruding from the imaginary buttress surface J is 20 mm.sup.2 or greater.

To provide a pneumatic tire excellent in steering stability and durability at high-speed driving, it is provided a pneumatic tire having a tread portion and a belt layer, wherein the tread portion is arranged on the outer side of the belt layer in the tire radial direction, the reinforcing cord in the belt layer is composed of cords made of monofilaments in which 50/5 cm or more of the monofilaments are arranged in the tire width direction in the tire radial cross section of the belt layer, and the maximum load capacity of the tire WL (kg) and the weight of the tire WT (kg) satisfy (WT/WL)≤0.0140.

To provide a pneumatic tire in which both low rolling resistance and improvement of noise performance at high-speed driving are sufficiently achieved, it is provided a pneumatic tire having a tread portion and a belt layer, wherein the tread portion is arranged on the outer side of the belt layer in the tire radial direction, the reinforcing cord in the belt layer is composed of cords made of monofilaments in which 50 lines/5 cm or more of the monofilaments are arranged in the tire width direction in the tire radial cross section of the belt layer, and the maximum load capacity of the tire WL (kg) and the weight of the tire WT (kg) satisfy 0.0145≤(WT/WL).

This invention relates to a rubber compound for tire treads, comprising:

30 to 70 parts by weight per hundred parts by weight rubber (phr) of a cyclopentene ring-opening rubber having a Tg of −120° C. to −80° C. and a ratio of cis to trans of 5:95 to 40:60; and 20 phr to 60 phr of a high vinyl polybutadiene rubber.

An additive for rubber that enables a rubber composition to have excellent low heat generating property and processability, a rubber composition containing the additive for rubber, and a tire using the same are provided. A rubber composition comprises a hydrazone compound represented by the following Formula (I): ##STR00001##
where R.sup.1 and R.sup.2 each independently represent a hydrogen atom, an alkyl group with a carbon number of 1 to 16, or an alkenyl group with a carbon number of 2 to 6, and A represents a group represented by the following Formula (A-1) or Formula (A-2): ##STR00002##

A pneumatic tire 1 comprises a carcass 6 extending between bead cores of bead portions via a tread portion 2 and sidewall portions, and a belt layer 7 arranged on an outer side in a tire radial direction of the carcass 6 and inside of the tread portion 2. The pneumatic tire 1 further comprises a damping rubber body 30 arranged between the carcass 6 and the belt layer 7, and a noise damper 20 arranged on an inner cavity surface of the tread portion 2. A width W1 in a tire axial direction of the damping rubber body 30 is in a range of from 60% to 130% of a width W2 in the tire axial direction of the belt layer 7, and a water absorption rate of the noise damper 20 is in a range of from 10% to 25%.

The present invention provides a pneumatic tire and a rubber composition for tires, which have improved durability at high temperatures and during high-speed running while ensuring good ice performance. The present invention relates to a pneumatic tire, including a tread, the tread including blocks having an average ripe density of 1.0 cm/cm.sup.2 or higher and an average height of 0.6 to 2.0 cm, the blocks containing a rubber composition having a tan δ at 100° C. of 0.179 or less as determined at an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz, and has a ratio of the modulus at 100° C. to the modulus at room temperature of 69% or greater as determined in accordance with JIS K6251:2010.

A vulcanizable composition comprising rubber component, a filler, and a curing agent, where the rubber component includes a block copolymer of polybutadiene and polyisoprene, and where the block copolymer has a cis content of at least 90%.