A ground contact region of the tread portion of a studdable tire includes a center region located over a range corresponding to a length of 5 to 25% of a ground contact width from a tire centerline on each of both sides of the tire centerline in a tire width direction; and two shoulder regions located on both sides of the center region in the tire width direction. In each of the center region and the shoulder regions, a plurality of the stud pin installation holes are disposed along each of four or more pin arrangement lines extending in a tire circumferential direction. An average value of adjacent intervals between the pin arrangement lines in the center region is larger than an average value of adjacent intervals between the pin arrangement lines in each of the shoulder regions.

A stud pin includes a tip, a body portion, and a lower flange. A flange profile shape of the lower flange is an anisotropic shape includes short sides and long sides of different lengths, and includes four or more first flange protrusion portions that project in the longitudinal direction parallel with the long sides and two second flange protrusion portions that project in the lateral direction parallel with the short sides. A body profile shape of the body portion is a shape including body linear portions extending in a linear manner. The body linear portions are disposed facing a portion of the flange profile shape between two adjacent protrusion portions of the first flange protrusion portion and the second flange protrusion portion along the outer circumference of the flange profile shape.

A tire mold comprises sector molds for forming a tread portion of a tire and mold pins provided on the sector molds for forming insertion holes in the tread portion. The insertion holes each comprise a first hole portion with a first inner diameter where a body portion of a stud pin is disposed and a second hole portion with a second inner diameter greater than the first inner diameter where a bottom flange portion of the stud pin is disposed. The mold pins each comprise a trunk portion with a first outer diameter for forming the first hole portion and a tip portion with a second outer diameter greater than the first outer diameter for forming the second hole portion.

A method for installing a stud in a tyre. The method includes identifying a stud hole for the stud in the tyre; imaging the vicinity of at least the stud hole, whereby information is received about the pattern in the vicinity of the stud hole, and using the received information to determine [i] the stud type suitable for the stud suitable in the stud hole and/or [ii] the suitable stud orientation of the stud suitable in the stud hole. The method includes providing a stud and installing it in a stud hole. The stud type of the stud is the same as the suitable stud type of a stud suitable in the stud hole; and/or the stud is installed in the stud hole in such a way that the main direction of the stud is parallel with the suitable stud orientation. Further a tyre studded by the method.

A stud pin includes a tip including a tip end surface configured to come into contact with a road surface and a trunk portion that supports the tip and extends in one direction. The trunk portion includes an upper flange disposed at a first end of the trunk portion, the tip being fixed to the upper flange, and a lower flange disposed at a position to a side opposite the upper flange of the trunk portion. An upper end surface of the upper flange from which the tip protrudes includes a recessed surface, the recessed surface including a smooth inclined surface recessing in a curved manner or a linear manner toward the lower flange with advancement toward a protruding base portion of the tip.

A heavy-duty tire includes a tread part formed such that the tread part includes a crown profile including tire equator, and a pair of shoulder profiles extending from outer sides of the crown profile to tread edges. In a tire cross section including tire rotation axis in 5% internal pressure state in which the tire is mounted to a normal rim, filled with air at internal pressure of 5% of normal internal pressure and loaded with no load, each of the crown and shoulder profiles has an arc shape convex toward tire radial direction outer side such that ratio Rc/Rs of curvature radius Re of the crown profile to curvature radius Rs of each shoulder profile is 7.0 or more, and a tire axial direction distance from the equator to a connecting point between the crown profile and each shoulder profile is 0.70 or more times a tread half width.

A pneumatic tire includes, in a tread, a plurality of blocks divided by grooves extending in a tire circumferential direction and grooves extending in a tire width direction, and a plurality of sipes and a stud pin hole disposed in the blocks. In such a tire, at least a portion of the sipes provided in a peripheral area of the stud pin hole comprises a raised bottom portion.

First direction ridge patterns and second direction ridge patterns are lined-up alternately at a decorative concave portion 18. Plural main ridges 22A through 22D and sub-ridges 26A through 26D, which project-out from a bottom surface 18A, are formed at a first direction ridge pattern 20. The respective ridges are disposed in parallel such that ridge extending directions are a same direction. Light reflection patterns are different at a main ridge region 24, 34 and a sub-ridge region 28, 38.

A stud pin includes a tip, a body portion that supports the tip, and a lower flange connected to the body portion at an end on an opposite side to the end surface. A profile shape of the lower flange and a body profile shape of the body portion are anisotropic shape. The flange profile shape includes four or more first flange protrusion portions projecting toward the longitudinal direction and two second flange protrusion portions projecting toward the lateral direction. The body profile shape includes four or more first body protrusion portions projecting toward the lateral direction and two second body protrusion portions projecting toward the longitudinal direction.

A stud pin includes a tip including an end surface that comes into contact with a road surface, a body portion that supports the tip; and a lower flange connected to the body portion at an end on an opposite side to the end surface. A profile shape of the lower flange is an anisotropic shape in which, of imaginary rectangles circumscribing the profile shape, a first smallest rectangle with the shortest side of its four sides being the shortest and/or a second smallest rectangle with the longest side of its four sides being the shortest includes short sides and long sides of different lengths. The profile shape includes four or more first protrusion portions that project in the longitudinal direction parallel with the long sides and two second protrusion portions that project in the lateral direction parallel with the short sides.