Tread (2) of a radial tire for a heavy vehicle. The tire alternatingly rolls in laden and unladen states on descent and ascent, respectively. Tread (2) has total width W.sub.T and comprises first median portion (21) having median width W.sub.c, where 0.2W.sub.T≤W.sub.c≤0.5W.sub.T. Tread (2) is axially delimited by second and third lateral portions (22, 23) having respective lateral widths (W.sub.S2, W.sub.S3) at least equal to 25% and at most equal to 40% of total width W.sub.T. Angle A.sub.51 of leading face (51) of every element in relief (31) of first median portion (21) is strictly greater than angle A.sub.61 of trailing face (61) of said element in relief (31). Angle (A.sub.52, A.sub.53) of leading face (52, 53) of every element in relief (32, 33) of each of the second and third lateral portions (22, 23) is strictly less than angle (A.sub.62, A.sub.63) of trailing face (62, 63) of said element in relief (32, 33).

A tread pattern of a pneumatic tire includes an inner circumferential main groove and an outer circumferential main groove that have groove walls extending in a tire circumferential direction while the angle of the groove walls relative to a contact surface varies with a predetermined amplitude, an inner lug groove extending from the inner circumferential main groove toward the outer circumferential main groove, an outer lug groove extending from the outer circumferential main groove toward the inner circumferential main groove, and a sipe configured to communicate the inner lug groove with the outer lug groove. A pair of chamfered surfaces are provided on walls of the sipe along an extension direction of the sipe on the contact surface.

A tire for running on rough terrain for which an intended tire rotational direction is specified. The tread portion is provided with blocks raised from a tread base portion. Each block has a first side wall surface comprising a radially outer portion extending substantially straight and radially inwardly, while inclining toward the toe side in the intended tire rotational direction, and a radially inner portion extending from the radially outer portion to the tread base portion while curving in an arc shape. The radially outer portion has a radial length of from 30% to 70% of a radial height of the block.

A tire for running on rough terrain for which an intended tire rotational direction is specified, and which comprises a tread portion provided with crown blocks disposed on the tire equator. Each of the crown blocks comprises a V-shaped crown block main portion which bends convexly toward a circumferential direction opposite to the intended tire rotation direction, and only two crown fin portions projecting from the crown block main portion toward the above-said circumferential direction opposite to the intended tire rotation direction.

A tire can include a block having a recess. The recess can include a first opening on a tread side and a second opening on a side wall face side. The first opening can include a pair of first edges extending from a first vertex to the side wall face side so as to form a V-shaped edge on the tread. The second opening can include a pair of second edges that can extend from a second vertex on the side wall face, and can be connected to the pair of first edges at intersection points. One of the pair of second edges can include a second edge body that can extend on a straight line from the second vertex to the intersection point, and a second edge subsidiary portion that can be bent so as to widen the second opening.

A tire comprises a tread portion having an outboard tread edge To and an inboard tread edge Ti. The tread portion is provided with: an outboard shoulder main groove extending continuously in the tire circumferential direction; an outboard crown main groove extending continuously in the tire circumferential direction and disposed between the outboard shoulder main groove and a tire equator; and outboard lateral grooves extending from the outboard crown main groove to the outboard tread edge To. The groove width of each of the outboard lateral grooves is decreased toward the outboard crown main groove 4.

Provided is a pneumatic tire having plurality of compound grooves, each including a lateral groove having a first end that communicates with a main groove on one side thereof and a second end that terminates inside a land portion, and further including a sipe that extends from the second end of the lateral groove to the main groove on the other side thereof, are formed at an interval in a tire circumferential direction in at least one row of the land portions positioned inside a center region. The compound grooves are disposed so that an opening direction of the lateral grooves relative to the main grooves alternatingly reverses in the tire circumferential direction. The lateral grooves each include a broad width portion and a narrow width portion.

A tire includes a plurality of circumferential main grooves extending in a tire circumferential direction, and a pair of shoulder land portions and one or more rows of center land portions defined by the plurality of circumferential main grooves. Further, at least one of the pair of shoulder land portions includes a plurality of shoulder lug grooves and a plurality of shoulder blocks defined and formed by the plurality of shoulder lug grooves. Additionally, at least a part of the plurality of shoulder blocks includes a notch portion that connects edge portions separated from a tire ground contact edge and a buttress portion. Additionally, the notch portion has a step-shaped wall surface in a cross-sectional view in a tire meridian direction.

Tread profile of a vehicle tire with profile elements (1,12,13,14,15,6) separated from one another by grooves (7,8,9,10,23), wherein the profile elements (13,14,1,12) separated by a groove (9,7) are outwardly delimited in the radial direction R by a radially outer surface (16) forming the ground contact area and toward the groove (9,7) respectively by a profile element flank forming a groove wall (17,18), wherein a rubber rib (20,19) extending in the extension direction of the groove (9,7) is respectively formed in the profile element flanks which delimit the groove (9,7) and each form a different groove wall (17,18) of the groove (9,7), wherein the rubber rib (19) formed in one groove wall (17) is formed in a different radial position of the vehicle tire than the rubber rib (20) formed in the other groove wall (18), wherein the two rubber ribs each (19,20) extend over the entire extension length of the profile element flank and wherein each of these two rubber ribs (19,20) respectively extends along its entire extension length from that profile element flank in which it is formed into the groove (9,7) in the direction of the other profile element flank up to at least the middle of the groove width in this radial position of the groove (9,7) and ends there in the groove (9,7) at a distance d2 from the profile element flanks.

The present invention relates to a tire with main kerfs and sub-kerfs, and more particularly, to a tire with main kerfs and sub-kerfs, which maintains drainage performance and running and braking performance by additionally including an auxiliary groove and improves a flow of air and drainage performance by including an auxiliary flow tube.