In a tire having composite grooves provided on a shoulder land portion, dry performance and wet performance are improved. The tire includes a tread portion 2. The tread portion 2 includes a first shoulder land portion 13. The first shoulder land portion 13 has shoulder lateral grooves 15 and shoulder composite grooves 20. The shoulder lateral grooves 15 and the shoulder composite grooves 20 are each curved so as to be convex in a tire circumferential direction. Each shoulder composite groove 20 includes, in a cross section thereof, a sipe element 21 having a width not greater than 1.5 mm and extending from a tread surface of the first shoulder land portion 13 in a tire radial direction, and a groove element 22 connected to an inner side in the tire radial direction of the sipe element 21 and having a width greater than 1.5 mm.

A tire can include a tread, sidewalls, beads, and a carcass. Each bead can include a core and an apex. A ratio of a height of the apex to a cross-sectional height of the tire may be not less than 5% and not greater than 15%. In a meridian cross-section of the tire in a standard state, a contour of a side surface including a maximum width position can include two arcs tangent to each other at the maximum width position. The arc located inward of the maximum width position in a radial direction can be a first arc, and the arc located outward of the maximum width position in the radial direction can be a second arc. A ratio of a first radius of the first arc to a second radius of the second arc may be not less than 70% and not greater than 91%.

A tire includes a tread portion including first and second tread edges, three or more circumferential grooves, and four or more land portions. The circumferential grooves include a first shoulder circumferential groove nearest to the first tread edge. Each land portion is provided with only sipes and is not provided with lateral grooves. The land portions include a first shoulder land portion having the first tread edge, and a first middle land portion adjacent to the first shoulder land portion. The first middle land portion is provided with first middle sipes traversing the first middle land portion completely in the tire axial direction. The first shoulder land portion is provided with first shoulder sipes extending from the first shoulder circumferential groove to the first tread edge. The first shoulder sipes have a circumferential pitch length smaller than a circumferential pitch length of the first middle sipes.

The present invention provides for a heavy truck tire tread (12) with a plurality of sipes (20) in the shoulder rib (18) that extend from the shoulder edge (14) to the shoulder groove (16). Each one of the sipes (20) has a bottom (28) with a teardrop (30) located at the bottom, and the bottom (28) does not extend the same depth in the thickness direction across the entire lateral length of the sipe (20). The bottom (28) at a middle of the sipe (20) extends for less of a depth in the thickness direction than does the bottom (28) at a shoulder edge (14) portion of the sipe (20) located outboard from the middle of the sipe (20) in the lateral direction. The bottom (28) at the middle of the sipe (20) extends for less of a depth in the thickness direction than does the bottom (28) at a shoulder groove (16) portion of the sipe (20) located inboard from the middle of the sipe (20) in the lateral direction.

A tread portion 2 includes four circumferential grooves 3 and five land portions 4. Each of the five land portions 4 is provided with no groove having a groove width greater than 2.0 mm, and is provided with only sipes 9. The four circumferential grooves 3 include a shoulder circumferential groove 5. The five land portions 4 include a shoulder land portion 11 and a middle land portion 13. The middle land portion 13 is provided with a plurality of middle sipes 30. The shoulder land portion 11 is provided with a plurality of shoulder sipes 20 each extending from the shoulder circumferential groove 5 to a position beyond a tread end. At least one of the shoulder sipes 20 includes an inclined portion 21. A maximum angle of the inclined portion 21 with respect to a tire axial direction is not greater than a maximum angle of the middle sipe 30 with respect to the tire axial direction. A difference between the maximum angle of the inclined portion 21 and the maximum angle of the middle sipe 30 is not greater than 5°.

A pneumatic tire includes chamfered sipes in a land portion each including a chamfered portion, and non-chamfered sipes in the land portion each not including the chamfered portion. The chamfered sipe includes one end communicating with the main groove that defines the land portion and the other end terminating within the land portion. The chamfered and non-chamfered sipes are alternately disposed in the circumferential direction. Of the non-chamfered sipes on both sides in the circumferential direction of the chamfered sipe, a relationship between a distance a and a distance b is in the range 1.5≤(b/a)≤12, where the distance a is between the chamfered sipe and a near sipe corresponding to the non-chamfered sipe located on a side closest to the chamfered sipe, and the distance b is between the chamfered sipe and the non-chamfered sipe located further from the chamfered sipe in the circumferential direction.

A tread block arrangement is suitable for a tire or for a tread band for a tire. The tread block arrangement includes a tread block having a first sipe delimited by a first sipe wall, a second sipe wall and a bottom of the sipe. The first sipe wall and the second sipe wall are arranged parallel to each other and define a width of the sipe. At least the first sipe wall has an indentation to increase an empty volume of the sipe at the location of the indentation. The first sipe wall has an inclined section to form the indentation, wherein a distance between the first sipe wall and the second sipe wall increases towards the bottom of the sipe at the location of the inclined section. A tire has the tread block arrangement and a lamella plate for forming sipes of the tread block arrangement.

A pneumatic tire includes, in a land portion, at least one circumferential sipe extending in the tire circumferential direction. At a first position, from the tread surface towards the sipe bottom, the sipe width gradually decreases from the tread surface to a first changing point and then gradually increases from the first changing point to the sipe bottom. At a second position, from the tread surface towards the sipe bottom, the sipe width gradually increases from the tread surface to a second changing point and then gradually decreases from the second changing point to the sipe bottom. The sipe width at the tread surface and at the sipe bottom gradually decreases in the tire circumferential direction from the first position towards the second position, and the sipe width in a tire radial intermediate portion gradually increases in the tire circumferential direction from the first position towards the second position.

A tire includes a tread portion including four circumferential grooves between outboard and inboard tread edges, and five land portions divided by the circumferential grooves. The circumferential grooves include an inboard shoulder circumferential groove located nearest to the inboard tread edge in the circumferential grooves. The land portions include an inboard shoulder land portion disposed axially outward of the inboard shoulder circumferential groove and having a ground contact surface with the smallest axial width in the land portions. The inboard shoulder land portion is provided with inboard shoulder lateral grooves and inboard shoulder sipes. The inboard shoulder lateral grooves include inner ends away from the inboard shoulder circumferential groove. The inboard shoulder lateral grooves extend axially outward from the inner ends to a location beyond the inboard tread edge. The inboard shoulder sipes extends from the inboard shoulder circumferential groove to a location beyond the inboard tread edge.

A tyre tread (10) has a groove (12) having a snow trapping device in the form of a dam (14) in it. The dam (14) is attached to a bottom wall (16) of the groove (12), and to side walls (18, 20) of the groove (12). The dam (14) has a first, snow trapping surface (22) and a second, inclined surface (24) which face in opposite sides in the groove longitudinal direction. The second, inclined surface (24) directs the flow of water away from the bottom wall (16). A hole (32) and a sipe (34) form a passageway (30) for water through the dam (14) in the groove longitudinal direction. The passageway reduces water flow recirculation. The whole of the dam (14) is between the side walls (18, 20) of the groove (12).