Tire (1) for an agricultural vehicle, and more particularly the tread (2) thereof, has improved traction in the field, while reducing the sensitivity of the lugs (3) to attack by stubble. Each lug (3) comprises first lug portion (31), having height H1, and second lug portion (32), having height H2 and having a mean angle of inclination A2 with respect to circumferential direction (XX′) of the tire. The first lug portion (31) is comprised of a radial superposition of N layers C1.sub.i (33), where i varies from 1 to N, each having a height H1.sub.i, each layer C1.sub.i having a mean angle of inclination A1.sub.i strictly less than the mean angle of inclination A2, and, when N is strictly greater than 1, the angle A1.sub.j relative to a layer C1.sub.j, where j varies from 1 to N−1, is strictly less than the angle A1.sub.j+1 relative to the layer C1.sub.j+1.

A pneumatic tire for an agricultural vehicle, comprising: a center rib and lugs that are joined integrally with two end surfaces of the center rib, and that are disposed respectively on one side and on another side of the center rib in the width direction thereof so as to be at intervals from each other in the tire circumferential direction on both the one side and the other side, wherein: the center rib has a width of from 30% to 50% of a tread width of the tread portion, and within a range where the lugs are disposed at 25% or greater of the tread width from the equator, the lugs are formed at an angle of from 20° to 50°, relative to a tire rotation axis direction, on an opposite side from a tire rotation direction, and a sum total of a surface area of ground-contacting surfaces of all of the lugs is from 4.5% to 15% of a surface area of the tread portion in a case in which the tread portion is unrolled as a flat surface and seen in plan view.

Agricultural vehicle tire having tread (1) with bearing surface (10) on which main lugs (3) and shorter secondary lugs (3) are formed on each side of the equatorial mid-plane (XX′), each secondary lug (3) interposed between two main lugs (2). The main lugs (2) and secondary lugs (3) make up, in the radial direction, a lens (21, 31) of a first material, each lens (21, 31) surmounted by a second material extending to the contact face of the main lugs and the secondary lugs. The viscous modulus G″1 of the first material is at most 60% of the viscous modulus G″2 of the second material. The complex modulus G*1 of the first material differs from the complex modulus G*2 of the second material, the difference between these complex moduli being at most 30% of the complex modulus G*2 of the second material.

A tread (2) for a driven axle of an agricultural vehicle, having a tread pattern elements (21) extending radially towards the outside from a bearing surface (22), the tread pattern elements having a total number N of tread pattern blocks (21) that are separated axially from one another, the tread pattern blocks having a contact face (211), a leading face (212) and a trailing face (213), the leading face being inclined at an angle α towards the rear with respect to the radial direction in the rolling direction (15) of the tread, the tread having a number n of tread pattern blocks in the case of which the angle α is between 50 degrees and 75 degrees, the number n being at least equal to 0.2×N.

A pneumatic tire includes a tread; sidewalls; beads inward of the sidewalls; lug grooves formed in the tread and inclined symmetrically about the equator, an inclination angle α of the lug grooves with respect to the lateral direction being 15°≤α≤45°; and shoulder grooves connecting the lug grooves and inclined in an opposite direction to the lug grooves, a center line of the shoulder grooves at both sides meeting with two of the lug grooves at intersection points. A difference between distances L1, L2 from the equator to the intersection points and a tread width TW satisfy TW×0.03≤|L1−L2|≤TW×0.2. An average value of the distances and the tread width TW satisfy TW×0.15≤(L1+L2)/2≤TW×0.35. A groove area ratio of the tread is from 0.4 to 0.7.

A motorcycle tire for running on rough terrain includes a tread portion. The tread portion includes a base surface and a plurality of blocks. The blocks include a crown block arranged on a tire equator side and a shoulder block arranged on a tread edge side. A height of the shoulder block from the base surface is larger than a height of the crown block from the base surface. The shoulder block is provided on the base surface side with a base portion that has a locally increased cross-section taken along the base surface.

A tire for running on rough terrain comprises a tread portion bound with an intended tire rotational direction. The tread portion comprises a row of crown blocks and rows of middle blocks. The crown blocks and the middle blocks each has an axially-elongated shape. A crown front edge of each of the crown blocks comprises a most concave portion positioned at the most toe-side thereof in the tire rotational direction and a pair of inclined edges extending from the most concave portion toward axially both sides thereof and toward the heel-side in the tire rotational direction. The inclined edges are each inclined at an angle from 10 to 45 degrees with respect to the tire axial direction. A middle front edge of each of the middle blocks extends axially outwardly and linearly over its entire length and is inclined to the heel-side.

A tire includes a tread surface portion with inclined grooves, 2ND longitudinal grooves, and shoulder longitudinal grooves; and an indicator portion that indicates a rotation direction of the tire in which a vehicle travels forward. The inclined groove gradually extends forward in the rotation direction toward a tire equator from the outside in the tire width direction. A front surface among inner surfaces defining the inclined groove includes a first side surface with an inner end portion to which the 2ND longitudinal groove is open, a second side surface positioned closer to an inside than the first side surface and of which an outer end portion is positioned closer to a rear side than the inner end portion of the first side surface, and a stepped surface that connects an inner edge of the first side surface to an outer edge of the second side surface and faces the outside.

A tire includes a circumferential direction groove and plural protrusions. The circumferential direction groove is formed in a tread face so as to open toward an outer side in a tire radial direction. The plural protrusions are formed so as to project to a projection height of from 0.1 mm to 1.0 mm from a groove bottom face or a groove side face of the circumferential direction groove, and are spaced apart by a spacing of from 0.1 mm to 1.0 mm. A center line MA, MB linking a center point of a leading end side with a center point of a base end side of each of the plural protrusions leans with respect to a perpendicular line HA, HB such that the leading end side of the protrusion is positioned further toward a tire rotation direction downstream side than the base end side of the protrusion when viewed along a tire width direction or the tire radial direction

A pneumatic tire includes alternating first and second groove portions. The first groove portion intersects an equator and extends in a width direction. The second groove portion inclines from the first groove portion to a tread edge at a smaller angle relative to a circumferential direction than an angle of the first groove portion relative to the circumferential direction. The first groove portion communicates with the second groove portion of the lug groove adjacent in the circumferential direction. The first groove portion is on a stepping side of each lug groove. The second groove portions are curved or bent and an average angle of the second groove portions in an inner region is smaller than in an outer region. Shallow grooves having a bent point are formed on blocks. The blocks are defined by circumferential narrow grooves connecting the second groove portions adjacent in the circumferential direction and the lug grooves.