Tire for a motorized two-wheeled vehicle

Abstract

The present invention provides a motorcycle tire that improves the turning performance at the initial stage of the roll of the vehicle body. A motorcycle tire (1) includes a tread reinforcing layer (7) composed of a jointless crown belt ply (8A). The jointless crown belt ply (8A) has a development width (Wa) of 65% or less of a tread development width (TWe). A ground contact profile (P) of a tread portion (2) includes a crown arc portion (Pc) having a curvature radius (R1) and a pair of shoulder arc portions (Ps) having a curvature radius (R2). The curvature radius (R1) is smaller than the curvature radius (R2) and is smaller than 50% of a tire cross-sectional width (Wt). In a normal state, an outer end (P1) of the crown arc portion (Pc) is positioned at a position that is located in an inner side of the tire axial direction from an outer end (8e) of the jointless crown belt ply (8A).

Description

Technical Field

[0001] This invention relates to tires for motorized two-wheeled vehicles. Background Technology

[0002] Patent Document 1 describes a pneumatic tire for motorized two-wheeled vehicles, which is configured with a helical belt layer at an angle of 0 to 5 degrees relative to the tire equator. The radius of curvature of this tire from the end of the helical belt layer to the end of the tread is larger than the radius of curvature from the end of the helical belt layer to the tire equator. Such a tire can improve traction performance from deep cornering to acceleration and stability when the vehicle is tilted.

[0003] Patent Document 1: Japanese Patent No. 5327957

[0004] In recent years, there has been a desire to improve the cornering performance during the initial stage of vehicle tilting in tires for motorized two-wheeled vehicles. Summary of the Invention

[0005] The present invention was made in view of the above-mentioned problems, and its objective is to provide a tire for motorized two-wheeled vehicles that can improve the turning performance in the initial stage of vehicle tilting.

[0006] This invention relates to a tire for motorized two-wheeled vehicles, comprising: a tread portion; an annular carcass; and a tread reinforcement layer disposed on the outer side of the carcass in the tire radial direction and on the tread portion. The tread reinforcement layer includes a crown belt layer, which is composed of a seamless crown belt ply consisting of crown belt cords spirally wound at an angle of less than 5 degrees relative to the tire circumference. The seamless crown belt ply has a spread width of less than 65% of the tread spread width centered on the tire equator. The contact surface profile of the tread portion includes a radius of curvature R1. The crown arc portion includes the tire equator; and a pair of shoulder arc portions with a radius of curvature R2, which extend from the outer ends of a pair of tire axial directions of the crown arc portion. The radius of curvature R1 is smaller than the radius of curvature R2, and the radius of curvature R1 is smaller than 50% of the tire cross-sectional width. In the normal state where the motor vehicle tire is assembled on a regular rim and adjusted to a regular internal pressure, the outer ends of the crown arc portion are respectively located inside the tire axial direction of the outer ends of the seamless crown cord ply.

[0007] The motorized two-wheeled vehicle tire of the present invention, by adopting the above-described structure, can improve the turning performance in the initial stage of vehicle tilting. Attached Figure Description

[0008] Figure 1 This is a radial cross-sectional view of a tire, illustrating one embodiment of the tire for motorized two-wheeled vehicles according to the present invention.

[0009] Figure 2 yes Figure 1 A diagram showing the unfolded tread of a tire.

[0010] Figure 3 This is a schematic diagram of the cross-section of the tread reinforcement layer.

[0011] Label Explanation

[0012] 1: Tire for motorized two-wheeled vehicles; 2: Tread surface; 7: Tread reinforcement layer; 8A: Seamless crown belt ply; 8e: Outer end of seamless crown belt ply; P: Ground contact surface profile; Pc: Crown arc portion; Ps: Shoulder arc portion; P1: Outer end of crown arc portion; TWe: Tread unfolded width; Wt: Tire cross-section width. Detailed Implementation

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0014] Figure 1 This is a cross-sectional view of the tire meridian, including the tire's axis of rotation (not shown), in its normal state, of the motorized two-wheeled vehicle tire (hereinafter sometimes simply referred to as "tire") 1 according to this embodiment. The tire 1 of the present invention is, for example, suitable for use as a tire for racing on a circular track. Such a tire 1 travels at relatively high speeds, thus promoting the growth of the tire 1's outer diameter. However, the tire 1 of the present invention is not limited to such racing tires.

[0015] The term "normal condition" refers to the state in which tire 1 is assembled on a normal rim (not shown) and adjusted to normal internal pressure, and is unloaded. In this specification, unless otherwise specified, the dimensions of tire 1 are values ​​measured under normal conditions.

[0016] In addition, "standard rim" refers to a rim with a specific specification determined for each tire within a specification system that includes the specification on which tire 1 is based. For example, if it is JATMA, it is "standard rim"; if it is TRA, it is "Design Rim"; and if it is ETRTO, it is "Measuring Rim".

[0017] In addition, "standard internal pressure" is the air pressure determined for each tire in the specification system, including the specification on which tire 1 is based. If it is JATMA, it is "maximum air pressure". If it is TRA, it is the maximum value recorded in the table "TIRE LOAD LIMITS ATVARIOUS COLD INFLATION PRESSURES". If it is ETRTO, it is "INFLATION PRESSURE".

[0018] like Figure 1As shown, the tire 1 of this embodiment includes a tread portion 2. The tread contact surface 2a, which is the outer surface of the tread portion 2, extends in an arc shape between a pair of tread ends Te, protruding outward in the radial direction of the tire. Such a tire 1 is capable of turning with a large camber angle.

[0019] Here, the tread end Te is the outer end of the tire axial direction that contacts the ground when the camber angle is at its maximum. In this embodiment, the position of the tread end Te of tire 1 is the position of the tire's maximum width. The length measured along the tread contact surface 2a between the two tread ends Te, Te is the tread unfolded width TWe. Furthermore, the center of the tire axial direction between the two tread ends Te, Te is the tire equator C.

[0020] The tire 1 further includes an annular carcass 6 and a tread reinforcement layer 7 disposed on the outer side of the carcass 6 in the radial direction of the tire and disposed on the tread portion 2. The carcass 6 in this embodiment is formed by a known structure.

[0021] Figure 2 This is a diagram showing the unfolded structure of tread reinforcement layer 7. (See diagram below.) Figure 1 and Figure 2 As shown, in this embodiment, the tread reinforcement layer 7 includes a crown belt layer 8. The crown belt layer 8 is formed of a seamless crown belt ply 8A formed by spirally winding crown belt cords 8c relative to the tire circumference at an angle θa of less than 5 degrees. Such a crown belt layer 8 suppresses the outer diameter growth of the tire 1, thereby achieving higher high-speed stability.

[0022] The seamless crown belt ply 8A has a tread width Wa of less than 65% of the tire's tread width TWe, centered on the tire equator C. Therefore, after the initial stage of vehicle tilting, since the seamless crown belt ply 8A is not located on the inner side of the tire's radial contact surface 2a in contact with the road surface, basic cornering performance is ensured.

[0023] The contact surface profile P of the tread 2 includes: a crown arc portion Pc with a radius of curvature R1, which includes the tire equator C; and a pair of shoulder arc portions Ps with a radius of curvature R2, which extend from the outer ends P1 of the pair of tire axial directions of the crown arc portion Pc. The contact surface profile P is the profile of the tread contact surface 2a in the radial section of the tire.

[0024] The radius of curvature R1 is the radius of the circle passing through three points: the first point C1 on the tire equator C of the contact patch profile P, and the two outer ends P1 and P2 of the crown arc portion Pc. Additionally, the radius of curvature R2 is the radius of the circle passing through three points: the inner end P2 of the tire axial direction of the shoulder arc portion Ps, the tread end Te, and the midpoint P3 along the length of the tread contact patch 2a between the inner end P2 and the tread end Te. The inner end P2 of the shoulder arc portion Ps coincides with the outer end P1 of the crown arc portion Pc.

[0025] The radius of curvature R1 is formed to be smaller than the radius of curvature R2. Furthermore, the radius of curvature R1 is formed to be smaller than 50% of the tire cross-section width Wt. This tread arc portion Pc improves handling during initial vehicle tilting, particularly agility (hereinafter sometimes simply referred to as "initial cornering performance"). In this specification, the tire cross-section width Wt is the axial distance of the tire at its maximum width position. In this embodiment, the tire cross-section width Wt is the axial length of the tire between the tread ends Te and Te.

[0026] The ratio of the radius of curvature R2 to the radius of curvature R1 (R2 / R1) is preferably 1.1 or more, more preferably 1.3 or more, preferably 3.0 or less, and more preferably 2.0 or less. When the ratio (R2 / R1) is less than 1.1, in other words, when the difference between the radius of curvature R2 and the radius of curvature R1 is small, the maneuverability from the initial to the final stage of vehicle tilting may decrease. When the ratio (R2 / R1) exceeds 3.0, for example, when the radius of curvature R2 is too large, smooth maneuvering from the middle to the final stage of vehicle tilting may become difficult. Furthermore, when the ratio (R2 / R1) exceeds 3.0, for example, when the radius of curvature R1 is too small, the stability during straight-line driving may decrease.

[0027] One pair of outer ends P1 of the crown arc portion Pc are located inside the tire axial direction of one pair of outer ends 8e, 8e of the seamless crown belt ply 8A. Therefore, even during high-speed driving that causes the outer diameter of the tire 1 to grow, the seamless crown belt ply 8A can suppress the outer diameter growth at the outer ends P1 of the crown arc portion Pc, maintaining the radius of curvature R1 of the crown arc portion Pc. As a result, high initial cornering performance is maintained. In this specification, the phrase "located inside the tire axial direction of the outer ends 8e" includes the position where the outer ends 8e of the seamless crown belt ply 8A are located near the tread end Te of the imaginary line K connecting the outer ends P1 of the crown arc portion Pc and the center Oc of the radius of curvature R1.

[0028] Although not specifically limited, the spread length La between the outer end P1 of the crown arc portion Pc and the outer end 8e of the seamless crown belt ply 8A is preferably 2% or more of the tread spread width TWe, more preferably 4% or more, more preferably 10% or less, and more preferably 8% or less. Furthermore, the radius of curvature R1 of the crown arc portion Pc is preferably 40% or more of the tire section width Wt, more preferably 45% or more, and more preferably 55% or less. In this specification, the aforementioned "spread length" is the length along the tread contact surface 2a between the imaginary line K and the imaginary line K1 that passes through the outer end 8e and is parallel to the imaginary line K. Moreover, the spread width Wd of the crown arc portion Pc is preferably 30% to 60% of the tread spread width TWe centered on the tire equator C.

[0029] The unfolded width Wa of the seamless crown belt ply 8A is preferably 30% or more of the tread unfolded width TWe centered on the tire equator C, more preferably 35% or more. This maintains high stability during straight-line driving. To achieve better initial cornering performance, the unfolded width Wa of the seamless crown belt ply 8A is preferably less than 50% of the tread unfolded width TWe, more preferably less than 45%.

[0030] The crown cord 8c is preferably formed from organic fibers such as nylon fiber, polyester fiber, rayon fiber, polyethylene naphthalate fiber, and aramid fiber.

[0031] The tread reinforcement layer 7 also includes a belt layer 9. The belt layer 9 includes multiple belt ply layers 9A with multiple belt cords 9c arranged side by side. Each of the multiple belt ply layers 9A has a larger unfolded width Wa than the seamless crown belt ply layer 8A. Such belt ply layers 9A help to improve the rigidity of the tread 2 and generate greater lateral resistance.

[0032] The multiple belt-type ply layers 9A include: an outer belt-type ply layer 10 disposed on the outer side of the seamless crown belt ply layer 8A in the tire radial direction; and an inner belt-type ply layer 11 disposed on the inner side of the seamless crown belt ply layer 8A in the tire radial direction. Thus, in this embodiment, belt-type ply layers 9A are formed on both sides of the seamless crown belt ply layer 8A in the tire radial direction. This mitigates the hoop effect in the area where the seamless crown belt ply layer 8A is disposed, thereby suppressing the generation of lateral resistance. The tread contact surface 2a on the outer side of the seamless crown belt ply layer 8A in the tire radial direction contacts the ground from straight-line driving to the initial tilting of the vehicle body. Furthermore, the centrifugal force is small during the initial tilting of the vehicle body. Therefore, lateral resistance and centrifugal force can be balanced during the initial tilting of the vehicle body, thus further improving initial cornering performance.

[0033] The angle θo of the belt cord 10c of the outer belt ply 10 relative to the tire equator C is larger than the angle θi of the belt cord 11c of the inner belt ply 11 relative to the tire equator C. Generally, the belt cord 10c of the outer belt ply 10, which is closer to the tread contact surface 2a, has a greater impact on driving characteristics. In this embodiment, the angle θo of the belt cord 10c of the outer belt ply 10 is relatively large, thus enabling smooth handling during cornering.

[0034] The difference between angles θo and θi (θo-θi) is preferably between 10 and 40 degrees. Since the difference (θo-θi) is greater than 10 degrees, a basic hoop effect can be achieved. Since the difference (θo-θi) is less than 40 degrees, excessive increase in lateral resistance is suppressed, and the transition characteristics from the initial to the final stage of vehicle rollover, or from the final stage to the initial stage, are maintained at a high level.

[0035] The angle θo is preferably 70 degrees or more, more preferably 75 degrees or more, preferably 90 degrees or less, and more preferably 85 degrees or less. By making the angle θo 70 degrees or more, excessive hoop effect can be suppressed, good lateral resistance can be generated, and cornering performance can be improved. The angle θi is preferably 50 degrees or more, more preferably 60 degrees or more, preferably 80 degrees or less, and more preferably 70 degrees or less. By making the angle θi 50 degrees or more, excessive hoop effect can be suppressed, good lateral resistance can be generated, and cornering performance can be improved. By making the angle θi 80 degrees or less, an angle difference can be set between the angle θi and the belt cord 10c of the outer belt cord layer 10, and an effective hoop effect can be achieved.

[0036] The inclination direction of the belt cord 10c of the outer belt ply 10 relative to the tire equator C is preferably different from the inclination direction of the belt cord 11c of the inner belt ply 11 relative to the tire equator C. This allows for an effective clamping effect.

[0037] Although not particularly limited, the unfolded width Wb of the outer belt ply 10 is preferably 75% to 95% of the tread unfolded width TWe. In this embodiment, the unfolded width Wb of the outer belt ply 10 is formed to be smaller than the unfolded width Wc of the inner belt ply 11. Although not particularly limited, the unfolded length Lb between the outer end 10e of the outer belt ply 10 and the outer end 11e of the inner belt ply 11 is preferably 3% to 10% of the tread unfolded width TWe.

[0038] The belted cord 9c is preferably formed from organic fibers such as nylon fiber, polyester fiber, rayon fiber, polyethylene naphthalate fiber, and aramid fiber.

[0039] On both outer sides of the seamless crown belt ply 8A in the tire axial direction, a reinforcing rubber layer 13 is disposed between the outer belt ply 10 and the inner belt ply 11. This reinforcing rubber layer 13 improves the torsional stiffness in the outer region of the seamless crown belt ply 8A in the tire axial direction. Consequently, lateral resistance increases from the middle to the end of vehicle rollover, improving cornering performance.

[0040] Figure 3 This is a schematic diagram of the cross-section of the end of the tread reinforcement layer 7. (See diagram below.) Figure 3 As shown, within the configuration range of the reinforcing rubber layer 13, the minimum approach distance Lc between the outer belt cord layer 10 and the inner belt cord layer 11 is preferably 0.5 mm to 3 mm. Since the minimum approach distance Lc is 0.5 mm or more, the aforementioned effect can be effectively achieved. Since the minimum approach distance Lc is 3 mm or less, excessive increase in lateral resistance is suppressed, and the transition characteristics from the initial to the final stage of vehicle rollover are maintained at a high level.

[0041] The outer end 13e of the reinforcing rubber layer 13 in the tire axial direction is located further outward than the outer end 10e of the outer belt ply 10 in the tire axial direction. In other words, the outer end 10e of the outer belt ply 10 is located outward in the tire radial direction of the reinforcing rubber layer 13. Therefore, the minimum approach distance Lc of the belt cords is maintained at 0.5 mm to 3 mm between the outer ends 10e and 10e of the outer belt ply 10. Although not particularly limited, in this embodiment, the outer end 13e of the reinforcing rubber layer 13 in the tire axial direction coincides with the outer end 11e of the inner belt ply 11 in the tire axial direction.

[0042] While not specifically limited, the complex elastic modulus E*1 of the reinforcing rubber layer 13 is preferably 0.5 MPa or more, more preferably 0.7 MPa or more, more preferably 3.0 MPa or less, and more preferably 2.5 MPa or less. Since the complex elastic modulus E*1 of the reinforcing rubber layer 13 is 0.5 MPa or more, the torsional stiffness in the outer region of the tire axial direction of the seamless crown belt ply 8A can be effectively improved. Since the complex elastic modulus E*1 of the reinforcing rubber layer 13 is 3.0 MPa or less, excessive increase in stiffness in the outer region of the tire axial direction of the seamless crown belt ply 8A can be suppressed, thus maintaining a high level of transition characteristics from the middle to the end of vehicle rollover.

[0043] In this specification, the complex modulus of elasticity E* is a value measured under the following conditions using a dynamic viscoelasticity measuring device (Iplexer series) manufactured by GABO Corporation, in accordance with JIS-K6394.

[0044] Initial strain: 10%

[0045] Amplitude of dynamic strain: ±1%

[0046] Frequency: 10Hz

[0047] Deformation mode: Stretch

[0048] Measurement temperature: 70℃

[0049] like Figure 1 As shown, the tread portion 2 further includes a tread rubber 2G located radially outward of the outer belt ply 10. The tread rubber 2G forms the tread contact surface 2a. The complex elastic modulus E*2 of the tread rubber 2G is preferably greater than the complex elastic modulus E*1 of the reinforcing rubber layer 13. Such a tread rubber 2G can provide stability and optimal grip during driving. The complex elastic modulus E*2 of the tread rubber 2G is preferably 4.0 MPa or more, more preferably 5.0 MPa or more, more preferably 8.5 MPa or less, and more preferably 7.0 MPa or less.

[0050] The above describes in detail the particularly preferred embodiments of the present invention, but the present invention is not limited to the embodiments shown in the figures and can be implemented in various ways.

[0051] [Example]

[0052] Based on the specifications in Table 1, a prototype with... Figure 1 The basic structure of the tires for motorized two-wheeled vehicles was described. The prototype tires were mounted on the front wheels of a motorized two-wheeled vehicle, and the driver's senses were tested to evaluate initial cornering performance, mid-cornering performance, smooth transition characteristics during vehicle tilting, and ground feel as stability during vehicle tilting. Mid-cornering performance refers to handling, particularly agility, from the middle to the end of a tilt. The rear tires were of the same specifications. The results were expressed using a rating of 10 (Comparative Example 1), with higher values ​​indicating better performance in each area. Furthermore, the main commonalities are described below.

[0053] <Common Matters>

[0054] Front tire size: 120 / 70R17

[0055] Front tire pressure: 250 kPa

[0056] Front tire cross-section width Wt: 120mm

[0057] Rear tire size: 200 / 60R17

[0058] Rear tire pressure: 290 kPa

[0059] Motorized two-wheeled vehicle: 1000cc engine displacement

[0060] The results are shown in Table 1.

[0061] In Table 1, the "-" in the "La / TWe(%)" result indicates that the outer end of the crown arc is located on the outer side of the tire axial direction, which is closer to the outer end of the seamless crown cord ply.

[0062] [Table 1]

[0063]

[0064] The test results show that, compared with the comparative example, the tires of the embodiment improved the initial cornering performance.

[0065] [Postscript]

[0066] The present invention includes the following methods.

[0067] [Invention 1]

[0068] A tire for a motorized two-wheeled vehicle, comprising:

[0069] Fetal face;

[0070] The ring-shaped fetal body; and

[0071] A tread reinforcement layer, disposed on the outer side of the tire carcass in the radial direction and on the tread portion.

[0072] The tread reinforcement layer includes a crown band layer.

[0073] The crown belt layer is composed of a seamless crown belt fabric layer in which crown belt cords are spirally wound at an angle of less than 5 degrees relative to the tire circumference.

[0074] The seamless crown belt ply has a spread width of less than 65% of the tread spread width centered on the tire equator.

[0075] The contact surface profile of the tread area includes:

[0076] The crown arc portion with radius of curvature R1, which includes the tire equator; and

[0077] A pair of shoulder arcs with a radius of curvature R2, extending from the outer ends of a pair of tire axial sections of the crown arc.

[0078] The radius of curvature R1 is smaller than the radius of curvature R2.

[0079] The radius of curvature R1 is smaller than 50% of the tire cross-sectional width.

[0080] When the tire for the motorized two-wheeled vehicle is assembled on a standard rim and adjusted to the standard internal pressure, the outer ends of the crown arc portion are respectively located on the inner side of the tire axis than the outer ends of the seamless crown cord ply.

[0081] [Invention 2]

[0082] According to the tire for motorized two-wheeled vehicles of the present invention 1, wherein,

[0083] The ratio (R2 / R1) of the radius of curvature R2 to the radius of curvature R1 is 1.1 to 3.0.

[0084] [Invention 3]

[0085] According to the tire for motorized two-wheeled vehicles of the present invention 1 or 2, wherein,

[0086] The crown arc portion has a tread width of more than 30% of the tire's unfolded width, centered on the tire equator.

[0087] [Invention 4]

[0088] According to any one of the motorized two-wheeled vehicle tires of the present invention 1 to 3, wherein,

[0089] The seamless crown belt ply has a tread width of more than 30% and less than 50% of the tire equator.

[0090] [Invention 5]

[0091] According to any one of the motorized two-wheeled vehicle tires of the present invention 1 to 4, wherein,

[0092] The tread reinforcement layer also includes a belt layer.

[0093] The belt layer comprises multiple belted fabric layers with multiple belted cords arranged side by side.

[0094] The plurality of belted fabric layers each have a larger unfolded width than the unfolded width of the seamless crown fabric layer.

[0095] [Invention 6]

[0096] According to the tire for motorized two-wheeled vehicles of the present invention 5, wherein,

[0097] The plurality of belted fabric layers include:

[0098] An outer belt ply, disposed on the outer side of the seamless crown belt ply in the tire radial direction; and

[0099] The inner belt ply is disposed inside the tire radius direction of the seamless crown belt ply.

[0100] [Invention 7]

[0101] According to the tire for motorized two-wheeled vehicles of the present invention 6, wherein,

[0102] The angle θo of the belt cord of the outer belt ply relative to the tire equator is larger than the angle θi of the belt cord of the inner belt ply relative to the tire equator.

[0103] [Invention 8]

[0104] According to the tire for motorized two-wheeled vehicles of the present invention 7, wherein,

[0105] The difference (θo-θi) between the angle θo and the angle θi is 10 degrees to 40 degrees.

[0106] [Invention 9]

[0107] According to the tire for motorized two-wheeled vehicles of the present invention 7 or 8, wherein,

[0108] The angle θo is between 70 and 90 degrees.

[0109] The angle θi is 50 degrees to 80 degrees.

[0110] [Invention 10]

[0111] According to any one of the motorized two-wheeled vehicle tires of the present invention 6 to 9, wherein,

[0112] A reinforcing rubber layer is provided on both outer sides of the seamless crown belt ply along the tire axial direction, between the outer belt ply and the inner belt ply.

[0113] Within the configuration range of the reinforcing rubber layer, the minimum approach distance between the belt cords of the outer belted fabric layer and the inner belted fabric layer is 0.5mm to 3mm.

Claims

1. A tire for a motorized two-wheeled vehicle, comprising: Fetal face; The ring-shaped fetal body; and A tread reinforcement layer, disposed on the outer side of the tire carcass in the radial direction and on the tread portion. The tread reinforcement layer includes a crown band layer. The crown belt layer is composed of a seamless crown belt fabric layer in which crown belt cords are spirally wound at an angle of less than 5 degrees relative to the tire circumference. The contact surface profile of the tread area includes: The crown arc portion with radius of curvature R1, which includes the tire equator; and A pair of shoulder arcs with a radius of curvature R2, extending from the outer ends of a pair of tire axial sections of the crown arc. The radius of curvature R1 is smaller than the radius of curvature R2. The radius of curvature R1 is smaller than 50% of the tire cross-sectional width. The seamless crown belt ply has a tread width of more than 30% and less than 50% of the tire equator. When the tire for the motorized two-wheeled vehicle is assembled on a standard rim and adjusted to the standard internal pressure, one pair of outer ends of the tread arc portion are located on the inner side of the tire axis than one pair of outer ends of the seamless crown cord ply, and the unfolded length between one pair of outer ends of the tread arc portion and one pair of outer ends of the seamless crown cord ply is more than 2% and less than 10% of the unfolded width of the tread.

2. The tire for motorized two-wheeled vehicles according to claim 1, wherein, The ratio of the radius of curvature R2 to the radius of curvature R1, R2 / R1, is 1.1 to 3.

0.

3. The tire for motorized two-wheeled vehicles according to claim 1 or 2, wherein, The tread reinforcement layer also includes a belt layer. The belt layer comprises multiple belted fabric layers with multiple belted cords arranged side by side. The plurality of belted fabric layers each have a larger unfolded width than the unfolded width of the seamless crown fabric layer.

4. The tire for motorized two-wheeled vehicles according to claim 3, wherein, The plurality of belted fabric layers include: An outer belt ply, disposed on the outer side of the seamless crown belt ply in the tire radial direction; and The inner belt ply is disposed inside the tire radius direction of the seamless crown belt ply.

5. The tire for motorized two-wheeled vehicles according to claim 4, wherein, The angle θo of the belt cord of the outer belt ply relative to the tire equator is larger than the angle θi of the belt cord of the inner belt ply relative to the tire equator.

6. The tire for motorized two-wheeled vehicles according to claim 5, wherein, The difference between the angle θo and the angle θi, θo-θi, is between 10 degrees and 40 degrees.

7. The tire for motorized two-wheeled vehicles according to claim 5, wherein, The angle θo is between 70 and 90 degrees. The angle θi is 50 degrees to 80 degrees.

8. The tire for motorized two-wheeled vehicles according to claim 4, wherein, A reinforcing rubber layer is provided on both outer sides of the seamless crown belt ply along the tire axial direction, between the outer belt ply and the inner belt ply. Within the configuration range of the reinforcing rubber layer, the minimum approach distance between the belt cords of the outer belted fabric layer and the inner belted fabric layer is 0.5mm to 3mm.

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