A pneumatic tire includes a tread portion including a contact patch which occurs when the tire is mounted on a standard wheel rim with a standard pressure and loaded with a certain tire load at zero camber angle. The contact patch, on a respective tire load, defines a ratio Lc/Ls of a crown contact circumferential length Lc at an axial center of the contact patch to a shoulder contact circumferential length Ls at an axial location of 80% of an axial maximum width of the contact patch. The ratio Lc/Ls upon being loaded with 40%, of a standard tire load is equal to or less than 125% of the ratio Lc/Ls upon being loaded with 70% of the standard tire load.

A pneumatic tire has a tread having adjacent rib-shaped land portions (4) with circumferential grooves (3) therebetween. Annular elongate projection portions (5, 5) project toward each other from adjacent rib-shaped land portions (4). The elongate projection portions (5, 5) confronting each other are disposed with a spacing therebetween such that their mutually confronting tip surfaces (5s, 5s) make contact with each other due to elastic deformation of the rib-shaped land portions (4, 4) at the time of grounding of the tire. An inside groove space (6) is formed on a radially inner side of the confronting elongate projection portions (5, 5) and an outside groove space (7) is formed on a radially outer side of the elongate projection portions (5, 5). The tip surfaces (5s) of the elongate projection portions (5) are formed with a plurality of communication recesses (9) providing communication between the inside and outside groove spaces (6, 7). The communication recesses (9) are formed at intervals in a tread circumferential direction. It is thus possible to enhance rigidity of the rib-shaped land portions over the whole tread at the time of grounding of the tire, thereby to suppress elastic deformation of the rib-shaped land portions and to reduce rolling resistance, while securing a draining property attributable to the circumferential grooves.

A tire includes a tread part having main grooves and lands demarcated by the main grooves. A crown land between a pair of crown main grooves includes first crown lug grooves extending from one crown groove to tire axial direction inner side and terminated within the crown land, second crown lug grooves extending from the other crown groove to the tire axial inner side and terminated within the crown land, and first crown sipes formed at tire circumferential direction positions and connecting the crown grooves, each first crown sipe includes a first side crown sipe piece extending from one crown groove to the tire axial inner side, a second side crown sipe piece not positioned on an extension line of the first side piece and extending from the other crown groove to the tire axial inner side, and a connecting crown sipe piece connecting the first and second sipe pieces.

A tread has a midcircumferential plane, a first axial tread edge, and a second axial tread edge. The tread includes a first shoulder rib extending circumferentially about a perimeter of the tread, a second shoulder rib extending circumferentially about the perimeter of the tread, and a first intermediate rib extending circumferentially about the perimeter of the tread. The first intermediate rib is defined by a first and a second circumferentially extending groove disposed to each axial side of the first intermediate rib. The first intermediate rib has a first plurality of angled sipes extending both axially and circumferentially at an angle between 50 and 70 relative to the first circumferentially extending groove. The angled sipes each have a radial depth of between 1.0 mm and 3.0 mm.

A modified road bicycle assembly for riding quickly over uneven road surfaces includes a bicycle frame with a top tube, a down tube, a head tube, and a seat tube. A saddle is removably engaged to an upper end of the seat tube. A handle bar is removably engaged to an upper end of the head tube. The bicycle frame is a road bike frame and the handle bar is a drop handle bar. A suspension fork is attached to the bicycle frame and extends downwardly from the head tube. A rear shock is attached to the top tube and extends rearwardly and downwardly from the top tube. A front tire is rotatably mounted to the suspension fork. A rear tire is rotatably mounted to the rear shock.

The pneumatic tire includes, on a tread surface, at least two circumferential main grooves and at least one rib-like land portion defined by two of the circumferential main grooves. The rib-like land portion includes neither grooves nor sipes that extend to include a widthwise center line of the rib-like land portion. The rib-like land portion includes a one-end-open sipe and a both-end-closed sipe. The one-end-open sipe has a widthwise sipe portion and a circumferential sipe portion, the widthwise sipe portion extending in tire width direction from one end of the one-end-open sipe and being terminated within the rib-like land portion, and the circumferential sipe portion being located closer to the widthwise center line than the both-end-closed sipe, extending in tire circumferential direction from the widthwise sipe portion, and being terminated at another end of the one-end-open sipe.

Provided are tractor wheels for a downhole tractor. An example tractor wheel comprises a series of continuous springs disposed on the circumference of the tractor wheel, wherein the individual continuous springs in the series of continuous springs are separated by a gap, and a void disposed on the interior of the tractor wheel and that is continuous about the circumference of the tractor wheel.

A tire having an outer middle land portion demarcated between an outer shoulder circumferential groove and an outer crown circumferential groove and located at an outer side of a vehicle when the tire is mounted on the vehicle, and an inner middle land portion demarcated between an inner shoulder circumferential groove and an inner crown circumferential groove and located at an inner side of the vehicle when the tire is mounted on the vehicle formed in a tread portion. The outer middle land portion has first outer middle sipes extending from the outer crown circumferential groove toward the outer shoulder circumferential groove and terminating within the outer middle land portion. The inner middle land portion has first inner middle sipes extending from the inner shoulder circumferential groove toward the inner crown circumferential groove and terminating within the inner middle land portion. An angle 1 of each first outer middle sipe with respect to a tire axial direction is smaller than an angle 2 of each first inner middle sipe with respect to the tire axial direction.

This pneumatic tire includes, on the tread surface, land portions defined by circumferential main grooves extending continuously in the tread circumferential direction and by tread edges. An intermediate land portion on one side in the tread width direction, adjacent to the tire equatorial plane side of the outermost circumferential main groove on the one side, is formed into blocks only by sipes extending in the tread width direction, an intermediate land portion on the other side in the tread width direction, adjacent to a tire equatorial plane side of an outermost circumferential main groove on the other side, is formed in a ribbed shape, and intermediate land portion lug grooves are formed in the intermediate land portion on the other side, with one end opening into the outermost circumferential main groove on the other side, and the other end terminating within the intermediate land portion on the other side.

A tire includes a tread portion being provided with a pair of circumferentially and continuously extending shoulder main grooves and at least one crown main groove between the shoulder main grooves to form a pair of middle portions each of which is between adjacent one crown main groove and one shoulder main groove. Each of the middle portions is provided with a circumferentially and continuously extending longitudinal sipe, a plurality of inner middle sipes extending axially outwardly from the crown main groove and terminating without reaching the longitudinal sipe and a plurality of outer middle sipe extending axially inwardly from the shoulder main groove and terminating without reaching the longitudinal sipe. The number of the outer middle sipes is greater than the number of the inner middle sipes.