A pneumatic tire includes circumferential grooves, lug grooves, land portions defined by the circumferential grooves and the lug grooves, and a narrow groove in the land portions that extends in a circumferential direction. At least one of the circumferential grooves that defines the land portions in which the narrow groove is disposed has an amplitude in a width direction while extending in the circumferential direction to be formed in zigzag shape including long and short portions having relatively different lengths. The narrow groove has one or more bent portions where an extension direction changes in the land portions to include a long portion and a short portion having relatively different lengths. The long portion of the narrow groove has an inclination direction in the width direction with respect to the circumferential direction in a direction opposite to the long portion of the at least one of the circumferential grooves.

A tire comprises a tread portion whose shoulder land part is provided with a narrow circumferential groove having an axially inner wall surface, an axially outer wall surface and a groove bottom including a deepest point. The axially inner wall surface has a radially inner curved portion concaved toward the axially inside, and the axially outer wall surface has a radially inner curved portion concaved toward the axially outside. the radially outer end of the radially inner curved portion of the axially inner wall surface is positioned radially inside the radially outer end of the radially inner curved portion of the axially outer wall surface.

The tire has a tread portion for which an intended tire rotational direction is specified. The tread portion comprises first inclined land portions defined between first inclined grooves. The first inclined land portion comprises an outer portion having a first wall surface and a second wall surface, and an inner portion having a third wall surface and a fourth wall surface. The angle θ1 of the first wall surface is smaller than the angle θ2 of the second wall surface, and the angle θ3 of the third wall surface is larger than the angle θ4 of the fourth wall surface.

A tyre includes a tread portion having a tread surface provided with grooves extending in a tyre axial direction. The grooves each include an opening formed on the tread surface, a minimum portion located inwardly in a tyre radial direction of the opening and having a groove width being locally minimum, and a maximum portion located inwardly in the tyre radial direction of the minimum portion and having a groove width being locally maximum in a region inwardly in the tyre radial direction of the opening.

A tyre includes a tread portion being provided with two circumferential grooves extending in a tyre circumferential direction to form a crown land portion therebetween. The crown land portion is provided with two or more crown grooves extending inwardly of the crown land portion from the respective circumferential grooves. Each crown groove includes wide-width regions and narrow-width regions having a groove width smaller than that of the wide-width regions, and the wide-width regions and the narrow-width regions are alternated.

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).

A tire has a tread surface, the tread surface including a circumferential groove extending in a tire circumferential direction, a lug groove extending in a direction intersecting the circumferential groove, and a plurality of land parts partitioned by the circumferential groove and the lug groove. A width-direction groove extending in a tire widthwise direction is formed on a land part of the plurality of land parts. An in-groove sipe is arranged along one side edge of a groove bottom of the width-direction groove.

Tread for heavy-duty vehicle tire, having tread surface in the new state, having a first volume of cavities opening onto the tread surface, a second volume of cavities formed entirely under the tread surface and having at least one channel of height Hc delimited by two main walls spaced apart from one another by a width Lc and connected together by a lower part and by an upper part, this channel intended to form, after partial wear corresponding to a thickness Lu, an additional groove, such that each channel has a plurality of extensions forming cavities extending between this channel and the tread surface over a height He at least equal to 20% and at most equal to 75% of the thickness Lu, each extension opening at least into the upper part of the channel through an opening having a cross-sectional area Sa at least equal to 0.8*(Hc*Lc).

A pneumatic vehicle tire, in particular a commercial vehicle tire, includes a tread which has a profile and has at least one circumferential groove (1) which is encircling in the circumferential direction, is embodied to a profile depth (P.sub.T) and in the cross section, starting at the tread external face, is composed of three adjoining groove portions, one outer groove portion (2) that expands in a funnel-shaped manner toward the outside, one 1 mm to 3 mm wide contracted groove portion, and one inner groove portion (4) which lies radially inward, is expanded in relation to the contracted groove portion (3) and has the largest cross-sectional face of all portions, and which is delimited by two cover flanks (4a), lateral groove flanks (4′b, 4″b) that adjoin said cover flanks (4a), and a groove base (4c).

A tread portion has a circumferential groove extending continuously and circumferentially. The circumferential groove has a groove bottom and a pair of groove walls radially extending from the groove bottom to a tread surface. The groove bottom includes groove bottom protruding portions protruding radially outwardly from a groove bottom reference surface parallel to the tread surface at a deepest position of a groove depth of the circumferential groove. Each of the groove bottom protruding portions is formed to be symmetrical about a center line of the circumferential groove in a plan view of the tread portion and has a first groove bottom surface extending radially. The first groove bottom surface includes a first surface portion on one side of the center line and a second surface portion on the other side. An angle between the first surface portion and the second surface portion is from 20° to 170°.