JP5138923B2 - Motorcycle tires - Google Patents

Description

  The present invention relates to a tire pair mounted on a motorcycle. In particular, the present invention relates to improvements in tire treads.

When the motorcycle turns, centrifugal force acts on the motorcycle. For cornering, a cornering force that balances this centrifugal force is required. When turning, the rider tilts the motorcycle inward. Turning is achieved by the camber thrust generated by this inclination. For the purpose of easy turning, motorcycle tires have a tread with a small radius of curvature. When going straight, the center area of the tread is grounded. On the other hand, when turning, the shoulder region is grounded. Japanese Unexamined Patent Application Publication No. 2005-271760 discloses a tire in which the roles of the center region and the shoulder region are considered.
JP-A-2005-271760

  Recent motorcycles are equipped with a high-power engine and have excellent braking performance. With improvements in motorcycle performance, tires are also required to have excellent turning performance and stability when traveling straight.

  If a hard tread is used, a large camber thrust can occur. This tread provides excellent turning performance. However, a hard tread hinders disturbance absorption performance.

  The turning performance is also affected by the grip performance of the tire. Low hardness tread contributes to grip performance. However, the low hardness tread is inferior in wear resistance. Furthermore, a low-tread tread impairs the stability performance when going straight.

  An object of the present invention is to provide a pair of motorcycle tires excellent in various performances.

  The motorcycle tire pair according to the present invention includes a front tire and a rear tire. Each of the front tire and the rear tire includes a red, a carcass having a ply including a cord made of an organic fiber and having a radial structure, and a belt positioned between the tread and the carcass. The tread includes a center region and a pair of shoulder regions positioned on the outer side in the axial direction than the center region. The center region and the shoulder region are made of a crosslinked rubber composition. In the front tire, the hardness Hs of the shoulder region is larger than the hardness Hc of the center region. In the rear tire, the hardness Hc of the center region is larger than the hardness Hs of the shoulder region.

  Preferably, in the front tire, the difference (Hs−Hc) between the hardness Hs and the hardness Hc is 3 or less. Preferably, in the rear tire, the difference (Hc−Hs) between the hardness Hc and the hardness Hs is 3 or less.

  The carcass of the front tire can include a first ply and a second ply. In each of the first ply and the second ply, the absolute value of the cord angle with respect to the equator plane is 65 ° or more and 80 ° or less. The inclination of the cord of the first ply with respect to the equator plane is opposite to the inclination of the cord of the second ply with respect to the equator plane. The carcass of the rear tire can include one ply. The absolute value of the angle of this ply cord with respect to the equator plane is not less than 85 ° and not more than 90 °.

  The belt of the front tire may include a cord wound spirally and extending substantially circumferentially. Preferably, the material of the cord is steel. The belt of the rear tire may include a cord wound spirally and extending substantially in the circumferential direction. Preferably, the material of the cord is aramid fiber or steel.

  Preferably, in each of the front tire and the rear tire, the ratio (Wc / Wt) of the half width Wc of the center region to the half width Wt of the tread is 0.25 or more and 0.75 or less. Preferably, in each of the front tire and the rear tire, a ratio (Ws / Wt) of the width Ws of the shoulder region to the width Wt is 0.25 or more and 0.75 or less.

  Preferably, the hardness Hc and hardness Hs of the front tire and the hardness Hc and hardness Hs of the rear tire are 55 or more.

  In the motorcycle tire pair according to the present invention, each tread of the front tire and the rear tire has an appropriate hardness distribution. This tire pair is excellent in various performances.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  FIG. 1 is a cross-sectional view illustrating a front tire 2 according to an embodiment of the present invention. In FIG. 1, the vertical direction is the radial direction, and the horizontal direction is the axial direction. The tire 2 has a substantially bilaterally symmetric shape with the one-dot chain line CL as the center. This alternate long and short dash line represents the equator plane. The tire 2 includes a tread 4, a wing 6, a sidewall 8, a bead 10, a carcass 12, a belt 14, an inner liner 16, and a chafer 18. The tire 2 is a tubeless type pneumatic tire. The tire 2 is attached to the front wheel of a motorcycle.

  The tread 4 has a shape protruding outward in the radial direction. The tread 4 forms a tread surface 20 that contacts the road surface. The tread 4 includes one center region 22 and a pair of shoulder regions 24. The center region 22 straddles the equator plane CL. The shoulder region 24 is located outside the center region 22 in the axial direction.

  The sidewall 8 extends substantially inward in the radial direction from the end of the tread 4. The sidewall 8 is made of a crosslinked rubber composition. The sidewall 8 absorbs an impact from the road surface by bending. Further, the sidewall 8 prevents the carcass 12 from being damaged.

  The bead 10 extends from the sidewall 8 substantially inward in the radial direction. The bead 10 includes a core 26 and an apex 28 that extends radially outward from the core 26. The core 26 has a ring shape and includes a plurality of non-stretchable wires (typically steel wires). The apex 28 is tapered outward in the radial direction. The apex 28 is made of a crosslinked rubber composition. The apex 28 has a high hardness.

  The carcass 12 includes a first ply 30 and a second ply 32. The first ply 30 and the second ply 32 extend along the inner surfaces of the tread 4 and the sidewall 8. The first ply 30 is folded around the core 26 from the inner side to the outer side in the axial direction. By this folding, the main portion 34 and the folding portion 36 are formed in the first ply 30. The folded portion 36 is laminated on the outer surface of the main portion 34. The end 38 of the second ply 32 is in contact with the inner surface of the sidewall 8. This end 38 does not reach the bead 10.

  Although not shown, the first ply 30 and the second ply 32 are each made of a cord and a topping rubber. The absolute value of the angle formed by the cord with respect to the equator plane CL is 65 ° or more and 80 ° or less. In other words, the tire 2 has a radial structure. The inclination of the cord of the first ply 30 with respect to the equator plane CL is opposite to the inclination of the cord of the second ply 32 with respect to the equator plane CL. When the absolute value of the angle is set to 65 ° or more and 80 ° or less, a large camber thrust is obtained. In this respect, the absolute value of the angle is more preferably 65 ° or greater and 75 ° or less. The cord is made of organic fiber. Examples of preferable organic fibers include nylon fibers, polyester fibers, rayon fibers, polyethylene naphthalate fibers, and aramid fibers.

  The carcass 12 may include other plies. However, the number of plies in the carcass 12 is preferably 2 from the viewpoint of light weight and suppression of longitudinal rigidity.

  The belt 14 is located between the carcass 12 and the tread 4. The belt 14 includes a belt ply 40. Although not shown, the belt ply 40 is composed of a cord and a topping rubber. The cord extends substantially in the circumferential direction and is wound spirally. The belt 14 has a so-called jointless structure. This belt 14 suppresses kickback and shimmy. The tire 2 provided with the belt 14 is excellent in disturbance absorbing performance. The belt may consist of two cut plies.

  The material of the cord of the belt 14 is steel or organic fiber. Specific examples of the organic fiber include aramid fiber, nylon fiber, polyester fiber, rayon fiber, and polyethylene naphthalate fiber. From the viewpoint of high restraining force and thus high rigidity, the preferred material of the cord is steel or aramid fiber. In particular, steel is preferred.

  The inner liner 16 is joined to the inner peripheral surface of the carcass 12. The inner liner 16 is made of a crosslinked rubber. For the inner liner 16, rubber having excellent air shielding properties is used. The inner liner 16 serves to maintain the internal pressure of the tire 2.

  The center region 22 and the shoulder region 24 are each made of a crosslinked rubber composition. The hardness Hc of the rubber composition in the center region 22 is small, and the hardness Hs of the rubber composition in the shoulder region 24 is large. In the tire 2, the center region 22 is mainly grounded when going straight. Due to the synergistic effect of the center region 22 having a small hardness Hc and the belt 14 having a jointless structure, the tire 2 exhibits excellent disturbance absorbing performance when traveling straight. In the tire 2, the shoulder region 24 is mainly grounded when turning. Since the shoulder region 24 has a high hardness Hs, a large camber thrust is generated even though the belt 14 having a jointless structure is used. In the tire 2, both disturbance absorption performance and turning performance are achieved.

  The difference (Hs−Hc) between the hardness Hs and the hardness Hc is preferably 3 or less. At the time of transition from straight traveling to turning traveling, the ground contact point transitions from the center region 22 to the shoulder region 24. Since the difference (Hs−Hc) is 3 or less, the behavior of the tire 2 does not change abruptly in the transition from the center region 22 to the shoulder region 24. At the time of transition from turning traveling to straight traveling, the ground contact point transitions from the shoulder region 24 to the center region 22. Since the difference (Hs−Hc) is 3 or less, the behavior of the tire 2 does not change abruptly in the transition from the shoulder region 24 to the center region 22. The tire 2 is excellent in transient performance. From the viewpoint of achieving both disturbance absorption performance and turning performance, the difference between the hardness Hs and the hardness Hc (Hs−Hc) is preferably 1 or more, and more preferably 2 or more.

  From the viewpoint of wear resistance, the hardness Hc is preferably 55 or more. From the viewpoint of disturbance absorbing performance, the hardness Hc is preferably 65 or less, and more preferably 63 or less. From the viewpoint of wear resistance, the hardness Hs is preferably 55 or more. From the viewpoint of camber thrust, the hardness Hs is more preferably 60 or more, and particularly preferably 64 or more. From the viewpoint of grip performance, the hardness Hs is preferably 70 or less.

  Hardness Hc and Hs are JIS-A hardness. The hardnesses Hc and Hs are measured by pressing a type A durometer against the tire 2 at room temperature.

  In FIG. 1, what is indicated by a double arrow Wt is a half width of the tread 4. The width Wt is a distance from the equator plane CL to the end of the tread 4. What is indicated by a double-pointed arrow Wc is a half width of the center region 22. The width Wc is a distance from the equator plane CL to the end of the center region 22. What is indicated by a double arrow Ws is the width of the shoulder region 24. The width Ws is a distance from one end of the shoulder region 24 to the other end. The widths Wt, Wc and Ws are measured on a sample obtained by cutting the tire 2.

  From the viewpoint of disturbance absorbing performance during straight travel, the ratio (Wc / Wt) is preferably 0.25 or more, and more preferably 0.4 or more. From the viewpoint of turning performance, the ratio (Wc / Wt) is preferably 0.75 or less, and more preferably 0.6 or less.

  From the viewpoint of turning performance, the ratio (Ws / Wt) is preferably 0.25 or more, and more preferably 0.4 or more. From the viewpoint of disturbance absorbing performance during straight travel, the ratio (Ws / Wt) is preferably 0.75 or less, and more preferably 0.6 or less.

  FIG. 2 is a cross-sectional view for explaining a manufacturing process of the tire 2 of FIG. In the manufacture of the tire 2, the inner liner 16, the first ply 30 and the second ply 32 are sequentially wound around a former (not shown). A ribbon 46 composed of a belt cord 42 and a topping rubber 44 is spirally wound on the second ply 32 to form a belt ply 40 having a jointless structure. The ribbon 46 extends substantially in the circumferential direction. A first strip 48 made of uncrosslinked rubber is wound on the belt ply 40 in a spiral shape. The first strip 48 extends substantially in the circumferential direction. The first strips 48 are sequentially stacked. When the first strip 48 has been wound, the second strip 50 made of uncrosslinked rubber is wound continuously with the first strip 48. The second strip 50 extends substantially in the circumferential direction. The second strips 50 are sequentially stacked. When the second strip 50 has been wound, the first strip 48 is further wound continuously with the second strip 50. A green tire is thus obtained. This green tire is put into a mold, and pressurized and heated. A cross-linking reaction occurs in the rubber by heating, and the tire 2 is obtained. A shoulder region 24 is obtained from the first strip 48. A center region 22 is obtained from the second strip 50. In the tire 2, since two types of strips 48 and 50 are used, the tread 4 including the center region 22 and the shoulder region 24 is easily formed. The tire 2 can be manufactured at a low cost.

  In the present invention, the size and angle of each member of the tire 2 are measured in a state where the tire 2 is incorporated in a regular rim and the tire 2 is filled with air so as to have a regular internal pressure. At the time of measurement, no load is applied to the tire 2. In the present specification, the normal rim means a rim defined in a standard on which the tire 2 depends. “Standard rim” in the JATMA standard, “Design Rim” in the TRA standard, and “Measuring Rim” in the ETRTO standard are regular rims. In the present specification, the normal internal pressure means an internal pressure defined in a standard on which the tire 2 relies. “Maximum air pressure” in JATMA standard, “Maximum value” published in “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” in TRA standard, and “INFLATION PRESSURE” in ETRTO standard are normal internal pressures.

  FIG. 3 is a cross-sectional view showing a rear tire 52 according to an embodiment of the present invention. In FIG. 3, the vertical direction is the radial direction, and the horizontal direction is the axial direction. The tire 52 has a substantially bilaterally symmetric shape with the one-dot chain line CL as the center. This alternate long and short dash line represents the equator plane. The tire 52 includes a tread 54, a wing 56, a sidewall 58, a bead 60, a carcass 62, a belt 64, an inner liner 66, and a chafer 68. The tire 52 is a tubeless type pneumatic tire. The tire 52 is attached to the rear wheel of the motorcycle.

  The tread 54 has a shape protruding outward in the radial direction. The tread 54 forms a tread surface 70 that contacts the road surface. The tread 54 includes one center region 72 and a pair of shoulder regions 74. The center region 72 straddles the equator plane CL. The shoulder region 74 is located outside the center region 72 in the axial direction.

  The carcass 62 includes one ply 76. The ply 76 extends along the inner surfaces of the tread 54 and the sidewall 58. The ply 76 is folded around the core 78 from the inner side to the outer side in the axial direction. By this folding, a main portion 80 and a folding portion 82 are formed in the ply 76. The folded portion 82 is stacked on the outer surface of the main portion 80.

  Although not shown, the ply 76 is made of a cord and a topping rubber. The absolute value of the angle formed by the cord with respect to the equator plane CL is 85 ° to 90 °. In other words, the tire 52 has a radial structure. By setting the absolute value of the angle from 85 ° to 90 °, excellent stability performance when traveling straight can be obtained. In this respect, the absolute value of the angle is more preferably 88 ° or greater and 90 ° or less. The cord is made of organic fiber. Examples of preferable organic fibers include nylon fibers, polyester fibers, rayon fibers, polyethylene naphthalate fibers, and aramid fibers.

  The carcass 62 may include other plies. However, the number of plies in the carcass 62 is preferably 2 or less, and more preferably 1 from the viewpoint of light weight and suppression of longitudinal rigidity.

  The belt 64 is located between the carcass 62 and the tread 54. The belt 64 includes a belt ply 84. Although not shown, the belt ply 84 is made of a cord and a topping rubber. The cord extends substantially in the circumferential direction and is wound spirally. The belt 64 has a so-called jointless structure. The tire 52 including the belt 64 is excellent in stability performance when traveling straight. The belt may consist of two cut plies.

  The material of the cord of the belt 64 is steel or organic fiber. Examples of preferable organic fibers include aramid fibers, nylon fibers, polyester fibers, rayon fibers, and polyethylene naphthalate fibers. From the viewpoint of high restraining force and thus high rigidity, the preferred material of the cord is steel or aramid fiber.

  The configurations of the sidewalls 58, the beads 60, and the inner liner 66 of the tire 52 are the same as those of the tire 2 shown in FIG.

  The center region 72 and the shoulder region 74 are made of a crosslinked rubber composition. The hardness Hc of the rubber composition in the center region 72 is large, and the hardness Hs of the rubber composition in the shoulder region 74 is small. In the tire 52, the center region 72 is mainly grounded when going straight. Due to a synergistic effect of the center region 72 having a large hardness Hc and the belt 64 having a jointless structure, the tire 52 exhibits excellent stability performance when traveling straight. In the tire 52, the shoulder region 74 is mainly grounded when turning. Since the hardness Hs of the shoulder region 74 is small, excellent grip performance is exhibited during turning. This grip performance contributes to the turning performance. In the tire 52, both the stability performance during straight traveling and the turning performance are compatible.

  The difference (Hc−Hs) between the hardness Hc and the hardness Hs is preferably 3 or less. At the time of transition from straight traveling to turning traveling, the ground contact point transitions from the center region 72 to the shoulder region 74. Since the difference (Hc−Hs) is 3 or less, the behavior of the tire 52 does not change abruptly at the transition from the center region 72 to the shoulder region 74. At the time of transition from turning traveling to straight traveling, the ground contact point transitions from the shoulder region 74 to the center region 72. Since the difference (Hc−Hs) is 3 or less, in the transition from the shoulder region 74 to the center region 72, the behavior of the tire 52 does not change abruptly. The tire 52 is excellent in transient performance. From the standpoint of achieving both the straight running stability performance and the turning grip performance, the difference (Hc−Hs) is preferably 1 or more, and more preferably 2 or more.

  From the viewpoint of wear resistance, the hardness Hc is preferably 55 or more. From the viewpoint of stability performance, the hardness Hc is more preferably 60 or more, and particularly preferably 64 or more. From the viewpoint of grip performance, the hardness Hc is preferably 70 or less. From the viewpoint of wear resistance, the hardness Hs is preferably 55 or more. From the viewpoint of grip performance, the hardness Hs is preferably 65 or less, and more preferably 63 or less.

  From the viewpoint of stable performance during straight traveling, the ratio (Wc / Wt) of the half width Wc of the center region 72 to the half width Wt of the tread 54 is preferably 0.25 or more, and more preferably 0.4 or more. From the viewpoint of grip performance during turning, the ratio (Wc / Wt) is preferably 0.75 or less, and more preferably 0.6 or less.

  From the viewpoint of grip performance during turning, the ratio (Ws / Wt) of the width Ws of the shoulder region 74 to the width Wt is preferably 0.25 or more, and more preferably 0.4 or more. From the viewpoint of stable performance during straight traveling, the ratio (Ws / Wt) is preferably 0.75 or less, and more preferably 0.6 or less.

  The tread 54 is also formed by spirally winding the first strip 48 and the second strip 50 in the same manner as the tread 4 shown in FIG. The tire 52 is easy to manufacture.

  The tire pair according to the present invention includes the front tire 2 shown in FIG. 1 and the rear tire 52 shown in FIG. In a motorcycle equipped with this pair of tires, when traveling straight, disturbance absorbing performance is exhibited by the front tire 2, and stability performance is exhibited by the rear tire 52. When turning, a large camber thrust is generated by the front tire 2, and excellent grip performance is exhibited by the rear tire 52. This tire pair is excellent in various performances.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

[Example 1]
A tire pair consisting of a front tire having the structure shown in FIG. 1 and a rear tire having the structure shown in FIG. 3 was obtained.

  The carcass of the front tire includes a first ply and a second ply. The carcass cord is made of nylon fiber. The fineness of this nylon fiber is 2/940 dtex. The absolute value of the angle of this cord with respect to the equator plane CL is 72 °. The belt is composed of one belt ply. This belt ply has a jointless structure (JLB). The belt ply includes a cord made of steel. The configuration of this code is “3 × 3 / 0.19”. The angle of this cord with respect to the equatorial plane CL is substantially zero. The tread is composed of a center region and a shoulder region. The hardness Hc of the center region is 62, and the hardness Hs of the shoulder region is 65. The ratio (Wc / Wt) is 0.50, and the ratio (Ws / Wt) is 0.50. The size of the front tire is “120 / 70ZR17”.

  The carcass of the rear tire is composed of one ply. The carcass cord is made of nylon fiber. The fineness of this nylon fiber is 2/1400 dtex. The absolute value of the angle of this cord with respect to the equator plane CL is 90 °. The belt is composed of one belt ply. This belt ply has a jointless structure. The belt ply includes a cord made of an aramid fiber. The fineness of this cord is 2/1670 dtex. The angle of this cord with respect to the equatorial plane CL is substantially zero. The tread is composed of a center region and a shoulder region. The hardness Hc of the center region is 64, and the hardness Hs of the shoulder region is 61. The ratio (Wc / Wt) is 0.60, and the ratio (Ws / Wt) is 0.40. The size of the rear tire is “190 / 50ZR17”.

[Examples 2 and 3]
Tire pairs of Examples 2 and 3 were obtained in the same manner as in Example 1 except that the ratio (Wc / Wt) and the ratio (Ws / Wt) of the rear tire were as shown in Table 1 below.

[Examples 4 and 5]
Tire pairs of Examples 4 and 5 were obtained in the same manner as in Example 1 except that the ratio (Wc / Wt) and ratio (Ws / Wt) of the front tire were as shown in Tables 1 and 2 below. .

[ Comparative Examples 3 and 4 and Example 8 ]
A tire pair of Comparative Example 3 was obtained in the same manner as in Example 1 except that the hardness Hs of the rear tire was as shown in Table 2 below. A tire pair of Comparative Example 4 was obtained in the same manner as in Example 1 except that the hardness Hc of the front tire was as shown in Table 2 below. A tire pair of Example 8 was obtained in the same manner as in Example 1 except that the hardness Hc and hardness Hs of the front tire and the hardness Hc and hardness Hs of the rear tire were as shown in Table 2 below.

[Examples 9 to 11]
A tire pair of Example 9 was obtained in the same manner as in Example 1 except that the material of the belt cord of the rear tire was steel having a configuration of “3 × 3 / 0.19”. A tire pair of Example 10 was obtained in the same manner as Example 1 except that the material of the belt cord of the front tire was aramid fiber having a fineness of 2/1670 dtex. Example 1 except that the material of the belt cord of the front tire is an aramid fiber having a fineness of 2/1670 dtex and the material of the belt cord of the rear tire is steel having a configuration of “3 × 3 / 0.19”. Similarly, a tire pair of Example 11 was obtained.

[Examples 12 and 13]
A tire pair of Example 12 was obtained in the same manner as in Example 1 except that the belt of the rear tire was composed of a cut ply. A cord made of an aramid fiber having a fineness of 2/1670 dtex was used for this belt. The absolute value of the angle of this cord with respect to the equator plane CL is 19 °. A tire pair of Example 13 was obtained in the same manner as in Example 1 except that the front tire belt was formed of a cut ply. A cord made of an aramid fiber having a fineness of 2/1670 dtex was used for this belt. The absolute value of the angle of this cord with respect to the equator plane CL is 19 °.

[Example 14]
A tire pair of Example 14 was obtained in the same manner as in Example 1 except that a carcass made of one ply was used for the front tire. The carcass cord is made of nylon fiber. The fineness of this nylon fiber is 2/1400 dtex. The absolute value of the angle of this cord with respect to the equator plane CL is 90 °.

[Comparative Example 1]
A tire pair of Comparative Example 1 was obtained in the same manner as in Example 1 except that the front tire tread had a single structure and the rear tire tread had a single structure.

[Comparative Example 2]
A tire pair of Comparative Example 2 was obtained in the same manner as Comparative Example 1 except that the front tire belt was formed of a cut ply. A cord made of an aramid fiber having a fineness of 2/1670 dtex was used for this belt. The absolute value of the angle of this cord with respect to the equator plane CL is 19 °.

[sensory evaluation]
The front tire was assembled in a rim of “MT3.50 × 17”, and this front tire was filled with air so that the internal pressure was 250 kPa. The rear tire was assembled in a rim of “MT 6.00 × 17”, and air was filled in the rear tire so that the internal pressure was 290 kPa. The tire pair was mounted on a motorcycle having a displacement of 1000 cc. This motorcycle was run on a racing circuit whose road surface is asphalt. The riders were evaluated for grip performance during turning, stability performance when going straight, turning performance and transient performance. The results are shown in Tables 1 to 4 below as indices. The higher the number, the better.

  As shown in Tables 1 to 4, the tire pairs of the examples are excellent in various performances. From this evaluation result, the superiority of the present invention is clear.

  The tire according to the present invention can be mounted on various motorcycles.

FIG. 1 is a cross-sectional view illustrating a front tire according to an embodiment of the present invention. FIG. 2 is a cross-sectional view for explaining a manufacturing process of the tire of FIG. FIG. 3 is a cross-sectional view illustrating a rear tire according to an embodiment of the present invention.

Explanation of symbols

2 ... Front tires 4, 54 ... Tread 8, 58 ... Side walls 10, 60 ... Beads 12, 62 ... Carcass 14, 64 ... Belts 16, 66 ... Inner liner 20, 70 ... Tread surface 22, 72 ... Center region 24, 74 ... Shoulder region 46 ... Ribbon 48 ... First strip 50 ... Second strip 52 ... Rear tire

Claims (5)

(1) a tread, a carcass having a radial structure including a ply including a cord made of an organic fiber, and a belt positioned between the tread and the carcass;
The tread includes a center region and a pair of shoulder regions positioned outside in the axial direction from the center region,
The center region and the shoulder region are made of a crosslinked rubber composition,
Hardness Hs of the shoulder area is much larger than the hardness Hc of the center region,
A front tire having a difference (Hs−Hc) between hardness Hs and hardness Hc of 3 or less; and (2) a tread, a carcass having a ply including an organic fiber and having a radial structure, and a tread and a carcass With a belt located between,
The tread includes a center region and a pair of shoulder regions positioned outside in the axial direction from the center region,
The center region and the shoulder region are made of a crosslinked rubber composition,
The hardness Hc of the center region is much larger than the hardness Hs of the shoulder area,
A motorcycle tire pair comprising a rear tire having a difference (Hc−Hs) between the hardness Hc and the hardness Hs of 3 or less . The carcass of the front tire is composed of a first ply and a second ply,
In each of the first ply and the second ply, the absolute value of the angle of the cord with respect to the equator plane is 65 ° or more and 80 ° or less,
The inclination of the cord of the first ply with respect to the equator plane is opposite to the inclination of the cord of the second ply with respect to the equator plane,
The carcass of the rear tire includes at least one ply,
The tire pair according to claim 1 , wherein an absolute value of an angle of the cord of the ply with respect to the equator plane is 85 ° or more and 90 ° or less. The belt of the front tire includes a cord wound spirally and extending substantially in the circumferential direction, and the material of the cord is steel,
The tire pair according to claim 1 or 2 , wherein the belt of the rear tire includes a cord wound spirally and extending substantially in the circumferential direction, and the material of the cord is aramid fiber or steel. In each of the front tire and the rear tire, the ratio (Wc / Wt) of the half width Wc of the center region to the half width Wt of the tread is 0.25 or more and 0.75 or less, and the width of the shoulder region with respect to the width Wt The tire pair according to any one of claims 1 to 3 , wherein a ratio of Ws (Ws / Wt) is 0.25 or more and 0.75 or less. The tire pair according to any one of claims 1 to 4 , wherein hardness Hc and hardness Hs of the front tire and hardness Hc and hardness Hs of the rear tire are 55 or more.

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