469results about "Motorcycle tyres" patented technology

Pairs of motorcycle tires and a method for improving performance and resistance to wearing, consists of a tread including grooves, the tread consisting of a central area, sided by intermediate side areas and by projection areas, the latter being adjacent to the external borders of such tread. The sea/land ratio in the central area of the front tire is between 15% and 30%; the sea/land ratio in such central area of the rear tire is substantially lower than that of the other areas of the tire, the value being lower than 70%; the sea/land ratio in the intermediate side areas of the front tire and rear tire is between 20% and 40%; and the sea/land ratio in the projection areas of the front tire and rear tire is between 10% and 30%.

A tire (10) is employed for the rear wheel of a motorcycle. A tread surface (16) is provided with a waveform groove (22), an intermediate groove (23) and a shoulder groove (24). The waveform groove (22) meanders in a circumferential direction over the central portion of the tread surface (16). The intermediate groove (23) is provided on the left and right of the waveform groove (22) along the waveform groove (22). The intermediate groove (23) is present in a predetermined region (ER). The intermediate groove (23) is formed like a boomerang having a long portion (32) and a short portion (31). An angle θ with respect to the axial direction of the long portion (32) is 45 to 75 degrees. The shoulder groove (24) is provided on an outside in the axial direction of the tread surface (16). An angle α of the shoulder groove (24) is set to be 25 degrees≦α≦50 degrees and α<θ.

A pair of motorcycle tires includes front and rear tires. The front tire's tread band includes at least one circumferential groove and a plurality of transverse grooves. The at least one circumferential groove extends at an equatorial plane of the front tire within a central zone of the tread band. The transverse grooves include axially inner ends lying within the central zone that alternately extend from the central zone toward axially opposite shoulder zones. At least some of the transverse grooves are connected to the at least one circumferential groove. The rear tire's tread band includes an area defining a substantially null sea/land ratio within a central zone of the tread band. The central zone of the rear tire's tread band has a width greater than or equal to about 5% and less than or equal to about 30% of an axial development of the rear tire's tread band.

An off-road tire for motorcycle comprises a tread portion provided with a plurality of blocks including an axially outmost shoulder block, a pair of sidewall portions, and a pair of bead portions, the shoulder block comprising a tread face with an axially outer edge corresponding to a tread edge and a lateral face extending from the tread edge to an radially inner edge located on the sidewall portion, the lateral face with a swelling portion swelling axially outside of the tire than a reference line which connects the tread edge and the radially inner edge, in a cross section including a tire axis, and the radial height of the radially inner edge of the lateral face from the bead base line being in a range of from 30 to 50% of the tire section height.

The tire for a two-wheeled vehicle comprises at a tread portion thereof shoulder rubber portions on tread end sides and a central rubber portion between the shoulder rubber portions. The central rubber portion is comprised of a once-wound body in which a wide flat rubber material has been wound once in the tire circumferential direction. The shoulder rubber portions are comprised of strip wound bodies in which a narrow and long rubber strip is spirally wound in the tire circumferential direction.

A pneumatic tire for a two-wheeled motor vehicle in which a belt layer 26 includes a spiral belt (26A) where the direction of its cords is substantially a circumferential direction of the tire, and at least one angled belt (26B) that is provided on at least an outer layer of the spiral belt (26A) and whose cords have an angle with respect to an equatorial plane of the tire. On a tread surface portion of a tread (22) of the tire, there is provided, at least in a tread center region, a main groove component having an angle in the range of 0° or more to less than 20° with respect to the circumferential direction. Thus, a pneumatic tire for a two-wheeled motor vehicle is provided that is applicable to a front or rear wheel, and that possesses improved kinematical performance including the turning capability at a corner, grip limit, overall settling of vibrations of a vehicle body, slip-control performance, capability of absorbing unevenness of a road surface, and enhanced steering stability, which are realized by making use of respective advantageous characteristics of the respective belts.

To provide a pneumatic tire for a motorcycle in which both wear resistance and wet steering stability can be attained. Since a pair of zigzag circumferential direction grooves 28 are positioned at the center of a tread central region 24C and has an amplitude, even when a certain camber angle is exceeded, an occurrence of a sudden separation of the zigzag circumferential direction groove 28 from a road-contact surface 26 can be prevented, whereby deterioration of wet steering stability can be suppressed. When the camber angle increases, water in a road-contact surface 26 is drained by inclining grooves 32 which are arranged at an external side of the zigzag circumferential direction groove 28. Since sharp inclining groove portions 32A of the inclining grooves 32 are positioned in the tread central region 24C, and no lug groove components are employed, circumferential direction rigidities of land portions in the tread central region 24C are high and exhibits excellent wear resistance. Since loose inclining groove portions 32B and sub-inclining grooves 38 of the inclining grooves 32 are positioned in tread side regions 24S, rigidities of land portions 40 resisting to inputs at the time of a large camber angle are high, and accordingly, wear resistance is high.

A motorcycle tire for running on rough terrain comprises a tread portion provided with a plurality of blocks including a cut block. The cut block is provided with a U-shaped cut so as to define a sub part of the cut block surrounded by the cut and a main part of the cut block outside the cut. The top surface of the sub part and the top surface of the main part are displaced from each other in a normal direction to the tread surface, and an exposed outside wall surface of the sub part and an exposed outside wall surface of the main part are displaced from each other in a lateral direction parallel with the tread surface, wherein the exposed outside wall surface of the sub part is defined as extending radially inwardly from the edge of the top surface of the sub part, and the exposed outside wall surface of the main part is defined as extending radially inwardly from the edge of the top surface of the main part and positioned on each side of the exposed outside wall surface of the sub part.

The present invention provides a pneumatic tire for motorcycle, in which driving properties and braking properties when a moderate camber angle is imparted to the tire on a dry road surface are improved without deteriorating stability in running, relatively large lateral force is reliably generated, and excellent wet performance is demonstrated without deteriorating dry performance of the tire, so that stable running is constantly enabled. The pneumatic tire for motorcycle, comprises: a tread portion 1 containing tread rubber 7 having a layered structure including at least one layer; a pair of sidewall 2 portions extending on the inner side in the radial direction and provided continuous with respective side portions of the tread portion 1; and bead portions 3 provided continuous with the inner peripheral sides of the respective sidewalls 2, wherein a ground contact region of the tread portion 1 is constituted of five regions consisting of: a center region 8 including the tire equatorial plane E; a pair of shoulder regions 9 including ground contact ends of the tread; and a pair of intermediate regions 10 located between the center region 8 and the respective shoulder regions 9, 100% modulus at the room temperature (25° C.) of intermediate tread rubber 7a provided across the entire part of each intermediate region 10 is set larger than each of 100% modulus of center tread rubber 7b provided across the entire part of the center region 8 and 100% modulus of shoulder tread rubber 7c provided across the entire part of each shoulder region 9, and a negative ratio in the ground contact region of the tread is set so as to gradually increase from the respective shoulder regions 9 toward the center region 8.

An off-road motorcycle tire having a block pattern comprising a plurality of blocks 11 defined by tread grooves 10, each block 11 having a circumferential profile 16 of top surface 12 in the form of a straight line or a circular arc having a radius Ra of curvature of at least 500 mm, in which the circumferential profile denotes a profile in the circumferential section which passes through the centroid G of the top surface 12 and is parallel to the tire equatorial plane Cc. According to the invention, the ground contact pressure at the periphery of the top surface of blocks 11 is prevented from lowering to enhance the edge effect.

A motorcycle tire for running on rough terrain comprises a tread portion (2) having a developed tread width (TWe) and provided with a plurality of tread blocks (B). The tread blocks include a plurality of crown blocks (13) defined as having a ground contacting top surface whose centroid (Gb) is located within a crown region (Cr) defined as having a developed width of 1/3 of the developed tread width (TWe) and centered on the tire equator. The crown blocks include a plurality of central crown blocks (13a) whose axial distance (L1) from the tire equatorial plane to the centroid is not more than 2 % of the developed tread width, and a plurality of off-center crown blocks (13b) whose axial distance (L2) from the tire equatorial plane to the centroid is more than 2 % and not more than 6 % of the developed tread width.

A device for transport of air in the tire P or close to it consisting of a chamber K in the shape of a hollow compressible channel, placed along at least a part of the tire perimeter, characterized by the fact that a ring OK is placed at the inner side of the chamber K with the distance of its outer side from the tire axis of rotation equal to 1 to 1.1 multiple of the distance of the bottom side of the chamber K from the axis of rotation of the tire P.

An insert specifically adapted for use with an off-road tire, such as an off-road tire of a motocross motorcycle, or an off-road bicycle. The insert includes an inflatable tube and a foam element which generally conforms to the contours of the off-road tire to provide support to the tire when the tube is inflated. The ability to deflate the insert facilitates installation of the insert between the wheel rim and off-road tire. When inflated, the insert occupies the space between the wheel rim and tire to support a load during use of the wheel.

The present invention provides a pneumatic tire for a motorcycle, in which tire durability at a relatively high speed in running straight is enhanced with maintaining good gripping performances in cornering situation by optimizing the distribution of loss tangent in tread rubbers constituting a tread portion. The pneumatic tire for a motorcycle includes a pair of bead portions 1 having bead cores embedded therein, a pair of sidewalls 2 extending on the outer side in the tire radial direction from the bead portions 1, and a tread portion 3 extending over the respective sidewall portions 2, wherein the tread portion 3 is constituted of at least four tread regions such that, when the tread regions are viewed in a section in the tire widthwise direction, loss tangent values of rubbers constituting the adjacent tread regions are different from each other, and a loss tangent value of a rubber constituting a center tread region 5 as a tread region including the tire equatorial plane 4, of the tread regions, is smaller than a loss tangent value of each of rubbers constituting other tread regions 6.

The present invention aims to provide a pneumatic tire for a motorcycle capable of improving turning performance on a wet road surface as compared to that of conventional tires. The pneumatic tire for a motorcycle comprises a tread 28 consisting of a tread central portion having a width of 60% of a tread developed width and tread side portions located outside of the tread central portion in the width direction of the tire and a plurality of wide inclined grooves 42 and narrow inclined grooves 44 inclined at an angle of less than 90 degrees with respect to the circumferential direction of the tire formed in the tread side portion such that the grooves continuously extend over a region of 50% or more of a width of the tread side portion. A groove width of the narrow inclined grooves 44 is set within a range between 0.3 mm and 2.5 mm. A total area of the wide inclined grooves 42 is set to not more than 20% of an area of the tread side portion. Such configuration can satisfy both of drainage performance and block stiffness of the tread contact portion in turning at a high level to obtain a higher grip force in turning on a wet road surface than that of conventional tires.

A radius of curvature (R1) of a corner portion (40) on one side (an inside in an axial direction) of a groove of a tyre (20) is smaller than a radius of curvature (R2) of the other corner portion (41). Both of the radii of curvature (R1) and (R2) are set to be 2 mm or more. A first phantom circle (42) for defining the corner portion (40) is inscribed on a second phantom circle (43) for defining the corner portion (41). A point of contact (44) of the first phantom circle (42) and the second phantom circle (43) is positioned on an outside from the center of a groove (28c). A distance between the center of the groove (28c) and the point of contact (44) is equal to or smaller than one fifth of a width (B) of the groove (28c).

A tire (18) includes a pair of beads (24), a carcass (26), a belt (28), and a band (30). The carcass (26) includes a carcass ply (44) having a carcass cord. The carcass cord is constituted by a rayon fiber or an aramid fiber. The belt 28 includes belt plies (46) and (48) having belt cords. The belt cord is constituted by an aramid fiber. The belt cord has a fineness which is equal to or greater than 1400 dtex and is equal to or smaller than 1600 dtex. The belt cord has a density which is equal to or higher than 20 ends/5 cm and is equal to or lower than 30 ends/5 cm. The band (30) includes a band ply (50) having a band cord. The band cord is wound spirally in a substantially circumferential direction.

A tire cord (10) comprises a core (11) made of aramid fibers twisted together at a twist pitch (P1), and a sheath (12) composed of at least one strand (14) made of aramid fibers and wound around the core at a winding pitch (P2), wherein the winding pitch (P2) is less than the twist pitch (P1), and the total fineness (A) of the aramid fibers constituting the core (11) is less than the fineness (B) of the aramid fibers constituting each strand (14) of the sheath (12). A pneumatic tire (1) comprising a reinforcing layer, e.g. tread reinforcing layer made of the tire cords (10).

A motorcycle tire 1 on rough terrain. Blocks 11 include crown blocks 16 arranged in a center area Cr of a tread portion 2, middle blocks arranged axially outside the crown blocks and shoulder blocks arranged axially outside middle blocks. The crown blocks have a smallest aspect ratio. The shoulder blocks have a largest aspect ratio. The crown block 16 includes a shift block. The shift block is provided in a center part in its widthwise direction with one circumferentially extending slit so as to divide the block into two small block segments. The two small block segments are shifted from each other in the tire circumferential direction.

There is provided a pneumatic radial tire for a motorcycle enabling safe running the motorcycle in conformity to various road conditions by achieving both performances of wet performance, i.e., hydroplaning and traction performances in particular, and linearity in handling at high level. In the pneumatic radial tire for a motorcycle, (a) tilt lug grooves are disposed at a tilt angle of 5 to 85° relative to a tire circumferential direction, (b) a ratio of the minimum length Lmin thereof to the surface length W thereof along one side of a tread is 0.1 or higher, (c) two groups of the tilt lug grooves are formed of two or more tilt lug grooves disposed substantially in parallel from each other, (d) they are formed of a first group of tilt lug grooves (G1) formed in a shape of chevron and a second group of tilt lug grooves (G2) formed in a shape of reversed chevron, (e) the G1 and G2 groups are alternately disposed in the circumferential direction, and (f) the G1 and G2 groups are mutually disposed on both sides of the equator of the tire line-symmetrically with respect to the equator and with an offset in the circumferential direction.

A tyre (1) for motor vehicles, having a tread band (8) extending around a rotation axis (Z) and comprising an annular central portion (A) astride of an equatorial plane (X-X) of the tyre, two annular shoulder portions (B) arranged on axially opposite sides with respect to the annular central portion (A) and two annular side portions (C) each arranged between the annular central portion (A) and a respective annular shoulder portion (B), the tread band (8) having at least one module (Ti; T2) replicated along a circumferential direction of the tyre and comprising: at least one plurality of primary grooves inclined with respect to the equatorial plane (X-X) and arranged at least on the annular portions (B), (C); at least one plurality of secondary recesses arranged mainly on the annular central portion (A) and on at least one annular side portion (C); wherein a substantial disappearance of the secondary recesses determines a difference in the empty/solid ratio on the annular central (A) and side (C) portions between a new tyre and a tyre that has traveled at least 2000 km greater than 1.7%.

A motorcycle tire having a block pattern suitable for running on rough terrain is disclosed. Each middle block overlaps with one of crown blocks at least partially in the tire circumferential direction. The top face of each crown block has an axially long rectangular shape. The top face of each middle block has a substantially pentagonal shape having five sides which are an axially inner side extending in the tire circumferential direction, a pair of transverse sides inclined so that the circumferential distance therebetween is gradually increased, and a pair of axially outer sides inclined so that the circumferential distance therebetween is gradually decreased. In a ground contacting patch of the tire in its normally inflated loaded condition and at the camber angle of zero, only an axially inner part of the top face of each middle block contacts with the ground.