A tread portion includes land portions divided by circumferential grooves. The land portions are provided with a set of lateral groove-shaped elements inclined with respect to tire axial and circumferential directions. Each lateral groove-shaped elements includes a circumferential first and second ends. The set of lateral groove-shaped elements is arranged in a first array over an entire circumference of the tire. The first array is such that in each of all pairs of two lateral groove-shaped elements adjacent to each other in the tire circumferential direction of the lateral groove-shaped elements, the first end of one of the two lateral groove-shaped elements is located at a circumferential same position as the second end of the other one of the two lateral groove-shaped elements. Two lateral groove-shaped elements included in at least one pair of the all pairs are formed on different land portions from one another.

Method for controlling the symmetry of the footprint area of a tyre miming on a straight trajectory with camber angle different from zero, wherein the method comprises the steps: —reducing the contact pressure of the tyre (2) on the footprint area at an inner shoulder (in case of negative camber) or at an outer shoulder (in case of positive camber); —disposing any medium line (Im) of the tread band (9) placed in correspondence with the footprint area substantially parallel to the ground; the invention also defines a tyre and a wheel for motor-vehicles, wherein the medium line (Im) of the tread hand (9) and the rotation axis (X-X) of the tyre (2) form an angle (a) substantially equal in absolute value to the camber angle (β); the invention also encompasses a process for manufacturing such tyres, wherein a green tyre with symmetric outer profile is deformed during the vulcanising and moulding step until a predetermined angle (a) different from zero is formed between any medium line (Im) of the tread band (9) and the rotation axis (X-X) of the vulcanised tyre (2).

A tire comprising a tread, the tread comprising at least one rubber layer of a rubber composition comprising a rubber component, a filler, and a silane coupling agent, wherein a ratio (G/W.sub.L) of a tire weight G (kg) with respect to a maximum load capability W.sub.L (kg) of the tire is 0.0150 or less, and, where Wt (mm) is the tire cross-sectional width and Dt (mm) is the tire outer diameter, Wt and Dt satisfy the following Mathematical expression (1), and an average value of tan δ at 15° C. to 30° C. of the rubber composition, which average value is measured under conditions of a frequency of 10 Hz, an initial strain of 10%, and an amplitude of ±0.5%, is 0.20 or less:

(π/4)×(Dt.sup.2/Wt)≥1700  (1)

In a pneumatic tire including a tread portion, a sidewall portion, a bead portion, a carcass layer mounted between a pair of bead portions, a plurality of main grooves extending in the tire circumferential direction and formed in the tread portion, and a plurality of land portions defined by the main grooves, the carcass layer includes a carcass cord formed of a polyester fiber cord, an elongation at break of the carcass cord is from 20% to 30%, and a groove area ratio SgA in a ground contact region of the tread portion is from 30% to 60%, a groove area ratio SgB in a center region of the tread portion satisfies a relationship 0.7≤SgB/SgA<1.1, and a depth of the main groove included in the center region is from 7 mm to 10 mm.

A non directional pneumatic tire is provided for an agricultural irrigation system. The tire includes first and second side walls and a radially outer wall defining an internal inflation chamber. A non directional tread pattern is defined on the tire and includes a plurality of longitudinal protrusions positioned substantially parallel to a rotational axis of the tire. The longitudinal protrusions are arranged in first and second rows extending from the first and second side walls toward and across the equatorial plane of the tire. The longitudinal protrusions of the first and second rows circumferentially alternate with each other and there is a circumferential spacing between adjacent longitudinal protrusions at the equatorial plane so that no portion of one longitudinal protrusion circumferentially coincides with or overlaps another.

An outer surface of a tire can include a tread surface and a pair of side surfaces. A contour line of the tread surface can include a center arc, a pair of middle arcs, a pair of side arcs, and a pair of shoulder arcs. A contour line of each side surface can be connected to the shoulder arc. A position, on the outer surface, corresponding to a ground-contact end obtained by applying a load that is 80% of a standardized load, to the tire in a standardized state, and bringing the tire into contact with a flat surface is a reference ground-contact position, and a boundary between the shoulder arc and the side arc is a reference boundary. The reference boundary can be located axially outward of the reference ground-contact position. A ratio of a distance in an axial direction from an equator plane to the reference boundary to a distance in the axial direction from the equator plane to a tread reference end TE can be not less than 0.94 and not greater than 0.98.

A tire with a tread reinforcing layer that includes a ply reinforcing structure formed by winding a cord-embedded rubber tape circumferentially of the tire. The ply reinforcing structure includes first oblique segments and second oblique segments which intersect with each other to form a mesh structure having rhombic spaces. The circumferential lengths of the rhombic spaces are less than ⅔ times the maximum circumferential length of the ground contacting patch of the tire in its normally loaded state.

A system is provided for estimating a tread depth of a tire supporting a vehicle. The tire includes a pair of sidewalls that extend to a circumferential tread. The system includes a drive over reader, which includes a housing. At least one sensor is mounted in the housing to generate an image of the tire, which may be an image of the tire footprint or an image of the tread along a lateral line or section, and the tread depth is determined from the image. At least one piezoelectric actuator is mounted on the housing and is electrically connected to the at least one sensor to actuate the at least one sensor. A method for estimating a tread depth of a tire supporting a vehicle is also provided.

In a tire 2, in a normal state, a profile of a tread surface 22 includes a crown circular arc as a circular arc representing a profile of a portion including an equator PC, and the crown circular arc has a radius of not less than 1600 mm and not greater than 2000 mm. On a ground-contact surface 52 obtained when a load is applied to the tire 2 in the normal state and the tread surface 22 is brought into contact with a flat road surface, an ultra-light load shape index F30 is higher than a light load shape index F60, the ultra-light load shape index F30 is not less than 1.10 and not greater than 1.20, and the light load shape index F60 is not less than 1.04 and not greater than 1.14.

When (I) a tyre 1 is in contact with a flat surface (S) with a camber angle θ of 40 degrees, (II) a load (F) applied to the tyre is increased from zero, and (III) a curve (T) is obtained by plotting, in a XY coordinate, a displacement (Δx) in a tyre axial direction and a displacement (Δy) in a tyre radial direction of a position (A) of one of tyre tread edges (Te) closer to the flat surface (S), the displacements being from a reference position (A0) when the load (F) is zero, inclination of the curve (T) increases as the load (F) increases at least in a range where the load (F) is not more than 78% of a maximum load capacity load of the tyre.