A tread (12) for a heavy truck tire is provided that has a bottom surface (14), a shoulder rib (16), and a sacrificial rib (20) located outboard from the shoulder rib (16) in a width direction. A decoupling void (30) is located between the shoulder rib (16) and the sacrificial rib (20). A decoupling void sipe (32) is in the shoulder rib (16) and opens at the shoulder rib upper surface (18) and at the decoupling void (30). The decoupling void sipe (32) extends in the thickness direction and is closer to the bottom surface (14) than the decoupling void (30) in the thickness direction.

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 tire having a tread portion, wherein the tread portion can include a pair of shoulder circumferential grooves, a pair of crown circumferential grooves, and a pair of middle land portions. Each middle land portion can include a plurality of middle sipes. Each middle sipe can have a chamfered portion at at least one of sipe edges on both opposite ends thereof. The chamfered portion can extend from the crown circumferential groove to the shoulder circumferential groove. A first chamfered width of the chamfered portion at a first one of the opposite ends on a crown circumferential groove side can be greater than a second chamfered width of the chamfered portion at a second one of the opposite ends on a shoulder circumferential groove side.

A tire that includes a tread portion having a designated mounting direction to a vehicle can comprise: an outer shoulder land portion having a greatest width, in the tire axial direction, of a ground contact surface among five land portions. The outer shoulder land portion can include a plurality of outer shoulder sipes connected to an outer shoulder circumferential groove. An outer middle land portion can include a plurality of outer middle sipes extending completely across the outer middle land portion in the tire axial direction. The outer shoulder sipes and the outer middle sipes each can include a pair of sipe walls. The outer shoulder sipes and the outer middle sipes can each include a body portion in which the pair of sipe walls are disposed substantially parallel to each other. A width of a body portion of each outer shoulder sipe can be greater than a width of a body portion of each outer middle sipe.

In a pneumatic tire, a sipe includes an edge on a leading side and an edge on a trailing side; the edge on the leading side and the edge on the trailing side each include a chamfered portion shorter than a sipe length of the sipe; a non-chamfered region in which other chamfered portions are not present is provided at portions facing the chamfered portions of the sipe; a maximum depth of the chamfered portion is less than a maximum depth of the sipe; a sipe width of the sipe is constant in a range from an end portion located on an inner side in a tire radial direction of the chamfered portion to a groove bottom of the sipe; and a raised bottom portion is disposed in at least one section of the chamfered portion.

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 modulus at 300% elongation of a cap tread ranges from 3.0 Mpa to 7.0 Mpa, a modulus at 300% elongation of a undertread ranges from 10.0 Mpa to 20.0 Mpa, and a modulus at 300% elongation of an earthing tread ranges from 10.0 Mpa to 20.0 Mpa. Additionally, an earthing tread is made from a rubber material with a volume resistivity of 1×10{circumflex over ( )}7Ω.Math.cm or less. The undertread includes a thickened portion in a region between the earthing tread and an edge portion of a block. The gauge of the undertread gradually increases from the earthing tread toward the edge portion of the block due to the thickened portion.

A tire includes a tread portion including a pair of shoulder main grooves and a crown region defined between the pair of the shoulder main grooves. The crown region includes a plurality of crown blocks. A ground contacting surface of at least one of the crown blocks is provided with a first sipe, a second sipe, and a third sipe. The first sipe, the second sipe, and the third sipe are connected with each other at one intersection.

Center land portions of a tire each include a circumferential narrow groove extending in a tire circumferential direction, and a first lateral groove opening to one edge portion of each of the center land portions at one end and connecting to the circumferential narrow groove at the other end, and a second lateral groove opening to the other edge portion of the center land portion at one end and connecting to the circumferential narrow groove at the other end. Further, the circumferential narrow groove has a zigzag shape formed by repeatedly connecting a first long portion, a first short portion, a second long portion, and a second short portion. Furthermore, the first lateral groove connects to the first long portion of the circumferential narrow groove having the zigzag shape, and the second lateral groove connects to the second long portion of the circumferential narrow groove having the zigzag shape.

Provided is a pneumatic tire including: a plurality of main grooves each having a zigzag shape and extending in a tire circumferential direction; and a land portion defined by the main grooves adjacent to each other and having a rib structure that is continuous with the tire circumferential direction. The land portion includes first and second lug grooves having a semi-closed structure. A maximum length L21 of the first lug groove in a tire width direction has the relationship 1.30≤L21/L22≤2.30 with respect to a maximum length L22 of the second lug groove.