In a pneumatic tire, shoulder blocks are formed with one of two types of values for block width measured in the tire circumferential direction. A cross-sectional shape of a tread ground contact edge of the shoulder blocks with the smaller block width value when sectioned in a plan that includes a tire axial center is formed with a squared portion formed by a curved line having a radius of curvature of 10 mm or less, or is formed with a squared portion taper cut along a straight line having a length of 10 mm or less. A cross-sectional shape of a tread ground contact edge of the shoulder blocks with the larger block width value when sectioned in the plan that includes the tire axial center is formed with a rounded portion formed by a curved line having a radius of curvature of from 30 mm to 60 mm inclusive.

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, a shape index of a reference ground contact surface is not less than 1.20 and not greater than 1.50. In the tire, a tread includes a cap layer, an intermediate layer formed such that a loss tangent of the intermediate layer at 30° C. is less than a loss tangent of the cap layer at 30° C. and a base layer formed such that a loss tangent of the base layer at 30° C. is less than the loss tangent of the intermediate layer at 30° C. In the radial direction, the intermediate layer is disposed outwardly of the base layer and the cap layer is disposed outwardly of the intermediate layer. In a shoulder land portion of the tread, a thickness of the cap layer at a center of an axial width is less than a thickness of the cap layer on the shoulder circumferential groove side.

A tire has a tread portion provided with circumferential grooves. The ground contact area of the tread portion has ground contact lengths in the tire circumferential direction which include a crown ground contact length LC at the tire equator C and a shoulder ground contact length LS at a position spaced apart from the tire equator C by 80% of a half tread width Tw. The crown ground contact length LC is 0.95 to 1.05 times the shoulder ground contact length LS. Groove depths of the circumferential grooves are proportional to ground contact lengths of the ground contact area at the respective axial positions of the circumferential grooves.

A tire has a tread portion provided with grooves. The ground contact area of the tread portion has ground contact lengths in the tire circumferential direction which include a crown ground contact length LC at the tire equator and a shoulder ground contact length LS at a position spaced apart from the tire equator by 80% of a half tread width Tw. The crown ground contact length LC is 0.95 to 1.05 times the shoulder ground contact length LS. Groove depths of the respective grooves are determined so as to satisfy specific mathematical equations based on a reference virtual groove G0 having a predetermined groove depth d0 and defined at the tire equator.

A tire includes knob sets having leading edge bevels connected by a ramp. The leading edge bevels may be offset in their positions or angles. Each knob set includes a first knob attached to a second knob. The knobs in each set may differ in lengths or in the angles of the leading edge bevels. Each knob set shares a common base and includes a pair of elongate outermost surfaces divided by an optional axial channel. Each knob set includes a lateral edge, medial edge and a trailing edge. Transverse rows of two or more knob sets may vary in lateral spacing between knob sets to provide narrow and wide rows in an alternating pattern. Knob sets may also be included on sidewalls of the tire.

A tire includes a tread portion including an outboard tread edge, an inboard tread edge, four circumferential grooves between the outboard and inboard tread edges, five land portions divided by the four circumferential grooves, and lateral grooves extending from the inboard tread edge to the crown land portion and terminating within the crown land portion. The four circumferential grooves include an inboard shoulder circumferential groove, an inboard crown circumferential groove, and an outboard crown circumferential groove. The five land portions include an inboard shoulder land portion, an inboard middle land portion, and a crown land portion between the inboard and outboard crown circumferential grooves. The crown land portion is provided with at least one crown sipe extending from the inboard crown circumferential groove or the outboard crown circumferential groove and terminating within the crown land portion, and crosses the axially center position of the crown land portion.

A tire includes a tread, a pair of sidewalls, a pair of beads, and a carcass. Each bead includes a core and an apex. In the tire in the normal state, a ratio (HA/HS) of a distance HA in a radial direction from a bead base line to an outer end PA of the apex to a tire cross-sectional height HS may not be less than 20% and/or may not be greater than 30%, and an angle of a line segment connecting between the outer end PA of the apex and a center PM of a width, in an axial direction, of a contact surface of the apex at which the apex is in contact with the core, relative to the bead base line, may not be less than 45° and/or may not be greater than 55°.

A mold includes a tread-forming surface to shape a tread surface. The tread-forming surface can include projections to form circumferential grooves, and land surface-forming portions to form land surfaces. Among the three land surface-forming portions aligned in an axial direction with the projections interposed therebetween, the land surface-forming portion located between the two projections can be a curved land surface-forming portion. A contour of the curved land surface-forming portion can be represented by one or more circular arcs. A boundary between a reference side surface of each projection and the curved land surface-forming portion can be a reference boundary point, and the reference boundary point can be located inward of a reference forming surface of the tread-forming surface.

A tire testing apparatus of drum type includes a drum having, on a circumferential outer surface thereof, a sensor for measuring a ground contact force of a tire and a transparent portion; an image capturing device for capturing, from inside of the drum and through the transparent portion, an image of the ground contact surface of a tire; a ground contact force measurement processing unit which measures a ground contact force of a tire in planner contact with the sensor; a ground contact surface image capture processing unit which captures an image of the ground contact surface by the image capturing device when the tire comes into planner contact with the transparent portion; and a slip amount calculation unit which calculates a slip amount based on a displacement of a corresponding location which corresponds to a ground contact surface of the tire for which a measurement is made.