A tire includes a circumferential tread extending in a circumferential direction circumscribing an axis of rotation. The circumferential tread includes a transverse groove having a plurality of protrusions protruding from a bottom portion of the transverse groove. One or more of a depth, a width, and a length of the transverse groove decreases in a direction parallel to the axis of rotation. The plurality of protrusions are circumferentially spaced apart across the bottom portion of the transverse groove.

There is provided a pneumatic tire with a reinforcing part which is mounted on a tire wheel, the pneumatic tire including: a tread having a groove that is formed in a circumferential direction of the tire wheel as being recessed toward a central axis of the tire wheel, a kerf that is formed to intersect the groove as being recessed toward the central axis of the tire wheel, and one or more blocks that are formed between the groove and the kerf and come into contact with a road surface; a shoulder formed at a side of the tread; and a reinforcing part inserted into the groove formed between the one or more blocks. The reinforcing part reduces noise produced due to contact with the road surface by being bent one or more times.

A pneumatic tire includes a circumferential main groove extending in a tire circumferential direction in a tread surface of a tread portion, wherein when the circumferential main groove is segmented into an outer side in a tire radial direction and an inner side in the tire radial direction by drawing an imaginary segment line parallel with a straight line connecting each of groove opening edges at a position of ½ of a groove depth in a meridian cross-section, a cross-sectional area SU on the outer side in the tire radial direction and a cross-sectional area SD on the inner side in the tire radial direction satisfy the relationship 0.15≤SD/SU≤0.60.

A pneumatic tyre including a tread portion, wherein the tread portion has a groove which is oriented at an angle between +45 and −45 degrees with respect to the rolling direction of the tyre, the groove having a depth extending in the radial dimension, wherein the groove includes a plurality of protrusions extending along the direction of the groove, wherein each protrusion has a length in the direction of the groove, a width perpendicular to its length and a height. Each protrusion has a length of at least 75% of the circumferential length of the tyre tread.

A pneumatic tire comprises a tread portion which has, on each side of the tire equator, a first tread edge, a second tread edge and a third tread edge which are occurred under tire loads of 100%, 75% and 50% of a regular tire load, respectively. Between the third tread edge and the tire equator, a circumferentially continuously extending main groove is disposed. A shoulder region between the main groove and the first tread edge is provided with a first inclined groove which extends so as to intersect with the first tread edge, the second tread edge and the third tread edge. The depth of the first inclined groove at the first tread edge is smaller than the depth at the second tread edge and the depth at the third tread edge.

A tire has a tread portion divided into a crown land region, shoulder land regions, and middle land regions. The crown land region comprises a crown axial central portion. The middle land region comprises a middle axial inner portion and a middle axial outer portion. The shoulder land region comprises a shoulder axial inner portion and a shoulder axial central portion. The radius Rmi of curvature of the middle axial inner portion is 0.80 to 1.20 times the radius Rcc of curvature of the crown axial central portion. The radius Rsc of curvature of shoulder axial central portion is 0.80 to 1.20 times the radius Rmo of curvature of middle axial outer portion. The radii Rsc and Rmo are less than the radii Rcc and Rmi. The radius Rsi of the shoulder axial inner portion is less than the radii Rsc and Rmo.

A tire includes a tread portion that includes a center main groove, an outer main groove provided on an outer side in a tire width direction of the center main groove, and a lug groove extending in a direction intersecting with both main grooves. The center main groove has a zigzag shape in which a first linear portion and a second linear portion are alternately connected. The outer main groove has a zigzag shape in which a long linear portion and a short linear portion are alternately connected. The lug groove has a groove center line intersecting with the short linear portion in the zigzag shape of the outer main groove.

In a tire, a main groove has a bend where the groove wall angle relative to the tread surface normal line changes in a meridian cross-section. In first and second blocks adjacent in a width direction with the main groove therebetween, an angle between a line extended from a ridge line formed by a bend of a first block side groove wall and a line extended from a lug groove wall defining the first block is larger than an angle between a line extended from the ridge line formed by a bend of the second block side groove wall and a line extended from a lug groove wall defining the second block, and an angle of the first block side groove wall to the tread surface normal line is smaller than an angle of the second block side groove wall to the tread surface normal line.

In a tire including a block having an edge along a main groove closer to an equatorial plane and a block having an edge along a main groove farther from the equatorial plane, the angles between an imaginary line extending a ridge line formed by a bend point of a groove wall on the edge side of the main groove and imaginary lines extending each of edges adjacent in a circumferential direction with the edge interposed therebetween are an acute angle (θa) and an obtuse angle (θb), and the angles between an imaginary line extending a ridge line formed by a bend point of a groove wall on the edge side of the main groove and imaginary lines extending each of edges adjacent in the circumferential direction with the edge interposed therebetween are an acute angle (θc) and an obtuse angle (θd), with a relationship (θd−θc)<(θb−θa).

A pneumatic tire according to an embodiment includes a main groove extending in a tire circumferential direction on a tread, and a plurality of protrusions protruding from a bottom of the main groove and connected to walls on both sides in a tire axial direction of the main groove. Each of the protrusions is provided with a narrow groove extending in an extending direction of the main groove and dividing the protrusion into both sides in the tire axial direction, and the bottom of the narrow groove is at a higher position than the bottom of the main groove.