JP2017039349A - Tire for two-wheeled motor vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance response performance and wet performance of a tire for a two-wheeled motor vehicle at a low camber time.SOLUTION: When a tread 9 of a tread part 2 between a tire equator CL and a tread end TE is divided into two parts comprising a center region M on the tire equator CL side and a shoulder region P on the tread end TE side, a tire 1 comprises an inclined main groove 24, which is so extended as to be inclined with respect to a tire circumferential direction S, in the center region M. An inclined shallow groove 33, which has a portion extending along the inclined main groove 24, is formed on an outer side in a tire width direction H of the inclined main groove 24. A length G1 of the inclined shallow groove 33 in the tire circumferential direction S is 50 to 100% of a length G2 of the inclined main groove 24 in the tire circumferential direction S.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a motorcycle tire having a main groove and a shallow groove shallower than the main groove in a tread portion.

  In motorcycle tires, various performances are required depending on the inclination (camber angle) at the time of turning. At low cambers where the camber angle is relatively small, response performance to occupant operations and wet performance on wet road surfaces are also required. The On the other hand, conventionally, a tire is known in which a plurality of main grooves and a plurality of sub-recesses are arranged in a predetermined pattern to maintain steering performance, drainage performance, and the like (see Patent Document 1).

  However, in the conventional tire described in Patent Document 1, the sub-recesses around the main grooves are too short compared to the main grooves, so that the sub-recesses may not sufficiently assist drainage of the main grooves. Moreover, the rigidity of the ground contact portion that is inside the turning of the main groove is high, and the effect of suppressing the slip in the lateral direction of the tire may be reduced at the time of low camber. Therefore, with conventional tires, it is difficult to improve both the response performance at the time of low camber and the wet performance to achieve both performances.

Special table 2012-513930 gazette

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to improve both the response performance and the wet performance of a motorcycle tire at the time of low camber so that both performances are compatible.

  The present invention is a motorcycle tire having a main groove and a shallow groove shallower than the main groove on a tread surface. When the tread surface between the tire equator and the tread edge is divided into two equal parts, the center area on the tire equator side and the shoulder area on the tread edge side, the motorcycle tire is in the tire circumferential direction in the center area. An inclined main groove extending inclinedly with respect to each other is provided. An inclined shallow groove having a portion extending along the inclined main groove is formed outside the inclined main groove in the tire width direction. The length of the inclined shallow groove in the tire circumferential direction is 50 to 100% of the length of the inclined main groove in the tire circumferential direction.

  ADVANTAGE OF THE INVENTION According to this invention, at the time of low camber, the response performance and wet performance of a motorcycle tire can be improved, and both performances can be made compatible.

1 is a cross-sectional view in the tire width direction of a motorcycle tire of the present embodiment. 1 is a plan view showing a tread pattern of a motorcycle tire of the present embodiment. It is a graph which shows distribution of the negative ratio in the motorcycle tire of this embodiment.

An embodiment of a motorcycle tire of the present invention will be described with reference to the drawings.
A motorcycle tire (hereinafter, referred to as a tire) according to the present embodiment is a pneumatic tire mounted on a motorcycle, and is mounted on various motorcycle rims (front wheel rim, rear wheel rim).
FIG. 1 is a cross-sectional view of the tire 1 of the present embodiment in the tire width direction H, and shows a cross section of the normal tire 1 cut in the tire width direction H.

  Here, the normal state is a state when the tire 1 is mounted on the normal rim, the tire 1 is filled with the normal internal pressure, and the tire 1 is unloaded. The dimensions, position, region, and the like related to the tire 1 are the size, position, region, and the like of the tire 1 in the normal state. Further, the normal rim and the normal internal pressure are defined by the standards applied to the tire 1. For example, in JATMA YEAR BOOK (Japanese Automobile Tire Association Standard), the regular rim is a standard rim, and the regular internal pressure is the highest air pressure. When other standards are applied in the place of use or manufacturing place of the tire 1, the normal state of the tire 1 is defined according to each standard. Other standards are, for example, YEAR BOOK of TRA (The Tire and Rim Association Inc.) in the United States, and STANDARDS MANUAL of ETRTO (The European Tire and Rim Technical Organization) in Europe.

  As illustrated, the tire 1 includes an annular tread portion 2 that is in contact with the road surface, a pair of bead portions 3 that are located inside the tire radial direction K of the tread portion 2, an end portion of the tread portion 2, and a bead portion 3. A pair of sidewall portions 4 are provided between them. The tire 1 includes an annular bead core 5 disposed in the bead portion 3, a carcass 6, a belt 7 disposed in the tread portion 2, and a tread rubber 8. The carcass 6 is formed by one or more layers of carcass plies, and is arranged from one bead core 5 to the other bead core 5. The belt 7 has a plurality of cords arranged in parallel, and is disposed outside the carcass 6 in the tire radial direction K.

  The tread rubber 8 is a portion in contact with the road surface of the tread portion 2 (outer peripheral portion of the tread portion 2), and is disposed outside the belt 7 in the tire radial direction K. The tread rubber 8 is disposed on the entire outer periphery of the tread portion 2, and the outer peripheral surface of the tread rubber 8 is a tread surface 9 of the tread portion 2. The tread surface 2 of the tread portion 2 is a ground contact surface (surface of the outer periphery of the tread portion 2) in contact with the road surface of the tread portion 2, and is located between the tread ends TE. The tread end TE is both ends of the tread surface 9 in the tire width direction H, and is located on the outermost side in the tire width direction H of the tread portion 2 (tread surface 9). The tire equator CL is located at the center in the tire width direction H of the tread surface 9 of the tread portion 2.

  In the cross section of the tread portion 2 in the tire width direction H, the width (tread width) of the tread portion 2 along the surface (tread surface 9) of the tread portion 2 is W, and the half width of the tread portion 2 along the surface of the tread portion 2 ( Tread half width) is L. The tread width W is a distance (periphery length) along the surface of the tread portion 2 between the tread ends TE. The tread half width L is a distance along the surface of the tread portion 2 between the tire equator CL and the tread end TE, and is a half value (W / 2) of the tread width W.

FIG. 2 is a plan view showing a tread pattern of the tire 1 according to the present embodiment, and shows a part of the tread portion 2 in the tire circumferential direction S developed.
As illustrated, the tire 1 includes a plurality of main grooves 21 to 23 and a plurality of shallow grooves 31 and 32 on the tread surface 9 of the tread portion 2. The shallow grooves 31 and 32 are subgrooves shallower than the main grooves 21 to 23, and the main grooves 21 to 23 and the shallow grooves 31 and 32 are formed in the tread rubber 8 of the tread portion 2.

  The depths of all the shallow grooves 31 and 32 are shallower than the depths of all the main grooves 21 to 23, and the widths of all the shallow grooves 31 and 32 are narrower than the widths of all the main grooves 21 to 23. For example, the depth of the main grooves 21 to 23 is 2 to 7 mm, and the depth of the shallow grooves 31 and 32 is 0.1 to 1 mm. The shallow grooves 31 and 32 improve the drainage performance of the tire 1 while ensuring the rigidity of the tread portion 2.

  The plurality of main grooves 21 to 23 extend in an inclined manner with respect to the tire circumferential direction S from one end on the tire equator CL side toward the other end on the tread end TE side. The main grooves 21 to 23 include a first main groove 21, a second main groove 22, and a third main groove 23, and are inclined in the same direction with respect to the tire circumferential direction S. The first main groove 21 is closest to the tire equator CL among the main grooves 21 to 23 and is formed in a curved shape. The second main groove 22 is located outside the first main groove 21 in the tire width direction H, and is formed between the first main groove 21 and the tread end TE.

  On both sides of the tire equator CL, the first and second main grooves 21 and 22 are formed between the two third main grooves 23, and the first and second main grooves 21 and 22 and the third main groove 23 are The tires are alternately arranged along the tire circumferential direction S. The second main groove 22 and the third main groove 23 are formed in a straight line and are arranged in parallel. One end of the first main groove 21 is located on the inner side in the tire width direction H (the tire equator CL side) than one end of the second main groove 22, and the other end of the second main groove 22 is the first main groove 21. It is located on the outer side (tread end TE side) in the tire width direction H than the other end.

  The shallow grooves 31 and 32 include a first shallow groove 31 and a second shallow groove 32. The first shallow groove 31 and the second shallow groove 32 are alternately arranged along the tire circumferential direction S on both sides of the tire equator CL. Be placed. The first shallow groove 31 is located outside the first main groove 21 in the tire width direction H, and is formed between the first main groove 21 and the second main groove 22. The first shallow groove 31 is adjacent to the first main groove 21 over the entire first main groove 21, and the first shallow groove 31 is first between the other end of the first main groove 21 and one end of the second main groove 22. It extends along the main groove 21. The second shallow groove 32 is formed between the first main groove 21 and the third main groove 23 so as to extend from the first main groove 21 to the tread end TE.

  On each side of the tire equator CL, the tread surface 9 (region of the tread half-width L) between the tire equator CL and the tread end TE is defined as a center region M (tire equator side region) on the tire equator CL side, Divided into two equal to the shoulder region P (tread end side region) on the tread end TE side (shoulder side). Between the tire equator CL and the tread end TE, the tread surface 9 of the tread portion 2 is equally divided into two in the tire width direction H at a half position (L / 2 position) of the tread half width L along the surface of the tread portion 2. Thus, the center region M and the shoulder region P are partitioned by the tread surface 9 of the tread portion 2. In the cross section of the tread portion 2 in the tire width direction H, the width along the surface of the tread portion 2 of the center region M and the shoulder region P is the same width, and the boundary between the center region M and the shoulder region P is from the tire equator CL. Along the surface of the tread portion 2, it is arranged at a position separated by L / 2.

  The tire 1 includes, in the center region M of the tread surface 9, an inclined main groove 24 that is inclined with respect to the tire circumferential direction S, and at least one inclined shallow groove formed outside the inclined main groove 24 in the tire width direction H. A groove 33 is provided. Here, the first main groove 21 is an inclined main groove 24 disposed in the center region M, and a part of the first shallow groove 31 is an inclined shallow groove 33 extending inclined with respect to the tire circumferential direction S. is there. The first shallow groove 31 includes two inclined shallow grooves 33 and other portions. The two inclined shallow grooves 33 are located outside the inclined main groove 24 in the tire width direction H and extend along the inclined main groove 24. The inclined main groove 24 and the inclined shallow groove 33 are inclined in the same direction with respect to the tire circumferential direction S, and a part of the inclined shallow groove 33 is formed in parallel with a part of the inclined main groove 24.

  The inclined shallow groove 33 is adjacent to the outside of the inclined main groove 24 in the tire width direction H, and is disposed in a region between one end and the other end of the inclined main groove 24. The length G1 of the inclined shallow groove 33 in the tire circumferential direction S is 50 to 100% of the length G2 of the inclined main groove 24 in the tire circumferential direction S, and the length G1 is (0.5 × G2). ) Or more (1.0 × G2) or less. The length G1 of the inclined shallow groove 33 is a distance in the tire circumferential direction S between two locations farthest in the tire circumferential direction S of the inclined shallow groove 33, and the length G2 of the inclined main groove 24 is the inclined main groove. 24 is a distance in the tire circumferential direction S between two points farthest in the tire circumferential direction S. The two inclined shallow grooves 33 are located between the inclined main groove 24 (first main groove 21) and the second main groove 22 and are formed adjacent to each other in parallel.

  The center region M is equally divided into an inner center region M1 inside the tire width direction H and an outer center region M2 outside the tire width direction H, and the shoulder region P is divided into an inner shoulder region inside the tire width direction H. Divided into P1 and outer shoulder region P2 outside in the tire width direction H. Between the tire equator CL and the tread edge TE, the tread surface 9 of the tread portion 2 is sequentially divided by a distance (L / 4) of a quarter of the tread half width L along the surface of the tread portion 2, and the tire width direction H Divided into four equal parts. As a result, the four regions M1, M2, P1, and P2 are partitioned on the tread surface 2 of the tread portion 2 with the same width. Comparing the negative ratios of the shallow grooves 31 and 32 in each of the regions M1, M2, P1, and P2, the negative ratio is the largest in the outer center region M2.

  The negative ratio of the shallow grooves 31 and 32 in each of the regions M1, M2, P1, and P2 is such that the shallow grooves 31 located in the regions M1, M2, P1, and P2 with respect to the areas of the regions M1, M2, P1, and P2, 32 area ratio. The areas of the regions M1, M2, P1, and P2 are the respective areas of the regions M1, M2, P1, and P2 in a state where the tread portion 2 has no tread pattern elements (grooves, convex portions, concave portions, or the like). The area of the shallow grooves 31, 32 is the total area (opening area) of the openings of the shallow grooves 31, 32 in the tread surface 9 of each region M1, M2, P1, P2. From the area of each region M1, M2, P1, P2 and the area of the shallow grooves 31, 32 located in each region M1, M2, P1, P2, the negative ratio of the shallow grooves 31, 32 is the region M1, M2, P1. , Calculated for each P2.

  The tread surface 2 of the tread portion 2 is further subdivided, and the negative ratios of the shallow grooves 31 and 32 and the main grooves 21 to 23 are compared. Here, on each of both sides of the tire equator CL, the tread surface 9 of the tread portion 2 between the tire equator CL and the tread end TE is divided into first to eighth regions F1 to F8 from the tire equator CL toward the tread end TE. Divide into 8 equal parts.

  Between the tire equator CL and the tread end TE, the tread surface 9 of the tread portion 2 is sequentially divided by a distance (L / 8) of the tread half width L along the surface of the tread portion 2, and the tire width direction H Divided into 8 equal parts. Thereby, the 1st-8th area | regions F1-F8 are divided by the tread part 2 on the tread part 2 by the same width. The first to fourth regions F1 to F4 are regions obtained by equally dividing the center region M of the tread surface 9 into four in the tire width direction H, and the fifth to eighth regions F5 to F8 include the shoulder region P of the tread surface 9 as a tire. This is a region equally divided into four in the width direction H.

  The negative ratio of the shallow grooves 31 and 32 in each region F1 to F8 is the ratio of the area of the shallow grooves 31 and 32 located in each region F1 to F8 to the area of each region F1 to F8. The area of each area | region F1-F8 is each area of the 1st-8th area | regions F1-F8 in the state in which the tread part 2 does not have the element (a groove | channel, a convex part, a recessed part, etc.) of a tread pattern. The area of the shallow grooves 31 and 32 is the total area (opening area) of the openings of the shallow grooves 31 and 32 in the tread surface 9 of each region F1 to F8. From the area of each region F1 to F8 and the area of the shallow grooves 31 and 32 located in each region F1 to F8, the negative ratio of the shallow grooves 31 and 32 is calculated for each region F1 to F8.

  The negative ratio of the main grooves 21 to 23 in each region F1 to F8 is the ratio of the area of the main grooves 21 to 23 located in each region F1 to F8 to the area of each region F1 to F8. The area of the main grooves 21 to 23 is the total area (opening area) of the openings of the main grooves 21 to 23 in the tread surface 9 of each region F1 to F8. From the areas of the regions F1 to F8 and the areas of the main grooves 21 to 23 located in the regions F1 to F8, the negative ratio of the main grooves 21 to 23 is calculated for each of the regions F1 to F8.

FIG. 3 is a graph showing the distribution of the negative ratio in the tire 1 of the present embodiment. The negative ratio N1 (%) of the shallow grooves 31 and 32 and the main grooves 21 to 23 in the first to eighth regions F1 to F8. Negative ratio N2 (%) is shown.
As illustrated, when comparing the negative ratio N1 of the shallow grooves 31 and 32 in each of the regions F1 to F8, the negative ratio N1 is the largest in the third region F3 (9% in FIG. 3). Further, the negative ratio N1 of the shallow grooves 31 and 32 in each of the regions F1 to F8 is the second largest in the eighth region F8 (3% in FIG. 3).

  In the regions F1, F2, and F4 to F7 other than the third and eighth regions F3 and F8, the negative ratio N1 of the shallow grooves 31 and 32 is the negative ratio of the shallow grooves 31 and 32 of the third and eighth regions F3 and F8. It is smaller than N1 and is a substantially constant value. In the regions F1, F2, and F4 to F7, the fluctuation of the negative ratio N1 of the shallow grooves 31 and 32 is small, and the negative ratio N1 of the shallow grooves 31 and 32 is a value within a predetermined allowable range. More specifically, in the present embodiment, the negative ratio N1 of the shallow grooves 31 and 32 in the regions F1, F2, and F4 to F7 is a value of 0 to 2%. Since the shallow grooves 31 and 32 are not formed in the first and second regions F1 and F2, the negative ratio N1 of the shallow grooves 31 and 32 in the first and second regions F1 and F2 is 0%.

  When comparing the negative ratio N2 of the main grooves 21 to 23 in each of the regions F1 to F8, the negative ratio N2 is the largest in the second region F2 (18% in FIG. 3). Further, the negative ratio N2 of the main grooves 21 to 23 in each of the regions F1 to F8 is the second largest in the fourth region F4 (11% in FIG. 3), and gradually increases from the sixth region F6 toward the eighth region F8. Get smaller. In the third to sixth regions F3 to F6, the negative ratio N2 of the main grooves 21 to 23 is smaller than the negative ratio N2 of the main grooves 21 to 23 of the second region F2, and is a substantially constant value. In the third to sixth regions F3 to F6, the fluctuation of the negative ratio N2 of the main grooves 21 to 23 is small, and the negative ratio N2 of the main grooves 21 to 23 is a value within a predetermined allowable range. More specifically, in this embodiment, the negative ratio N2 of the main grooves 21 to 23 in the third to sixth regions F3 to F6 is a value of 7 to 11%. Since the main grooves 21 to 23 are not formed in the eighth region F8, the negative ratio N2 of the main grooves 21 to 23 in the eighth region F8 is 0%.

  The tire 1 includes a plurality of circumferential shallow grooves 34 extending in the tire circumferential direction S in the eighth region F8 (see FIG. 2). Here, a part of the second shallow groove 32 is the circumferential shallow groove 34 formed in the eighth region F8, and the second shallow groove 32 includes the two circumferential shallow grooves 34 and other portions. The plurality of circumferentially shallow grooves 34 are spaced apart in parallel in the tire width direction H and extend linearly in the tire circumferential direction S. The length of the plurality of circumferential shallow grooves 34 in the tire circumferential direction S is the same length.

  Next, the operation and effect of the tire 1 at the time of low camber with a relatively small camber angle will be described. The low camber time is when the camber angle of the tire 1 tilted with respect to the vertical direction is up to 15 °. When the camber is low, the tire 1 is inclined at a camber angle of greater than 0 ° and less than 15 ° with respect to the vertical direction.

  As the vehicle turns, the tire 1 is tilted, and the camber angle of the tire 1 gradually increases. When the camber is low, the inclined main groove 24 is disposed in the center region M where the contact length becomes the longest, and the inclined main groove 24 ensures the drainage performance required for the tire 1. Further, drainage is assisted by the inclined shallow groove 33 having a portion extending along the inclined main groove 24, and the wet performance of the tire 1 is improved. The inclined shallow groove 33 is formed outside the inclined main groove 24 in the tire width direction H, and reduces the rigidity of the ground contact portion of the tread portion 2 inside the turning of the tire 1. Thereby, in the turning inside of the tire 1, generation | occurrence | production of the force of the front-back direction in the tread part 2 is suppressed, and the slip of the tire 1 in the horizontal direction is suppressed. As a result, the response performance (initial response performance) of the tire 1 with respect to the occupant's operation is improved.

  For example, when the main groove is formed instead of the inclined shallow groove 33, the main grooves are close to each other in the ground contact portion of the tread portion 2, and the rigidity may be excessively reduced. On the other hand, by forming the inclined shallow groove 33 outside the inclined main groove 24 in the tire width direction H, an excessive decrease in rigidity is suppressed, and the rigidity is moderated moderately. As a result, the response performance of the tire 1 is reliably improved.

  When the length G1 of the inclined shallow groove 33 in the tire circumferential direction S is shorter than 50% of the length G2 of the inclined main groove 24 in the tire circumferential direction S (0.5 × G2), drainage by the inclined shallow groove 33 is performed. There is a risk that this will affect the assistance of the arm and the relaxation of rigidity. Further, when the length G1 of the inclined shallow groove 33 is longer than 100% of the length G2 of the inclined main groove 24 (1.0 × G2), the rigidity of the tread portion 2 may be unnecessarily relaxed. is there. When the length G1 of the inclined shallow groove 33 is 50 to 100% of the length G2 of the inclined main groove 24, drainage is smoothly performed by the inclined shallow groove 33 and the wet performance of the tire 1 is ensured. To improve. At the same time, the inclined shallow groove 33 adjusts the rigidity of the ground contact portion of the tread portion 2, thereby reliably improving the response performance of the tire 1.

  As described above, in the tire 1 of the present embodiment, both the performance can be achieved by improving the response performance and the wet performance of the tire 1 at the time of low camber.

  The negative ratio of the shallow grooves 31 and 32 in the outer center region M2 is larger than the negative ratio of the shallow grooves 31 and 32 in the other regions M1, P1, and P2, and the shallow grooves 31 and 32 are most required to have wet performance. It is disposed most in the outer center region M2. The shallow grooves 31 and 32 of the outer center region M2 can reliably assist drainage while ensuring the rigidity required for the center region M2. Accordingly, the response performance and wet performance of the tire 1 at the time of low camber can be further improved.

  In order to reduce the influence on the wear resistance performance of the tire 1, the negative ratio of the shallow grooves 31, 32 in the inner center region M1 is made smaller than the negative ratio of the shallow grooves 31, 32 in the other regions M2, P1, P2. Is preferred. Further, the requirements for wet performance are small for the inner shoulder region P1 and the outer shoulder region P2, and it is not necessary to form many shallow grooves 31 and 32.

  The third region F3 is a region on the inner side in the tire width direction H among the regions obtained by dividing the outer center region M2 into two in the tire width direction H. When the negative ratio of the shallow grooves 31 and 32 in the third region F3 is larger than the negative ratio of the shallow grooves 31 and 32 in the other regions F1, F2, and F4 to F8, drainage is caused by the shallow grooves 31 and 32 during low camber. Assisted more reliably. Therefore, it is preferable that the negative ratio of the shallow grooves 31 and 32 in each of the regions F1 to F8 is maximized in the third region F3. Thereby, the wet performance of the tire 1 can be further improved.

  In order to reduce the influence on the wear resistance performance of the tire 1, the negative ratio of the main grooves 21 to 23 in the first region F1 is preferably smaller than the negative ratio of the main grooves 21 to 23 in the other regions F2 to F8. . In addition, with respect to the third region F3 to the eighth region F8, the requirement for wet performance is small, and it is not necessary to form many main grooves 21 to 23. Therefore, it is preferable to make the negative ratio of the main grooves 21 to 23 in the second region F2 larger than the negative ratio of the main grooves 21 to 23 in the other regions F1, F3 to F8. In this case, the wear resistance performance of the tire 1 can be improved, and the main grooves 21 to 23 are arranged most in the second region F2, so that the wet performance of the tire 1 can be further improved.

  The negative ratio of the shallow grooves 31 and 31 in each of the regions F1 to F8 is the second largest in the eighth region F8. Therefore, when the camber angle of the tire 1 is increased, the contact length in the tire width direction H of the tread portion 2 can be increased, and the grip performance of the tire 1 can be improved. By forming the plurality of circumferential shallow grooves 34 in the eighth region F8, when the camber angle of the tire 1 is increased, the rigidity in the tire width direction H of the ground contact portion of the tread portion 2 is reduced, so that the tire 1 The grip performance can be further improved.

  In the regions F1, F2, and F4 to F7 other than the third and eighth regions F3 and F8, the negative ratio of the shallow grooves 31 and 32 is a value within a predetermined allowable range (here, a value of 0 to 2%). The fluctuation of the negative ratio of the shallow grooves 31 and 32 is suppressed. Thereby, when the inclination of the tire 1 gradually increases and the camber angle of the tire 1 becomes 30 ° or more, the fluctuation of the inclination speed of the tire 1 can be reduced and the tire 1 can be inclined smoothly.

  DESCRIPTION OF SYMBOLS 1 ... Tire, 2 ... Tread part, 3 ... Bead part, 4 ... Side wall part, 5 ... Bead core, 6 ... Carcass, 7 ... Belt, 8 ... Tread rubber, 9 ... tread surface, 21 ... first main groove, 22 ... second main groove, 23 ... third main groove, 24 ... inclined main groove, 31 ... first Shallow groove, 32 ... second shallow groove, 33 ... inclined shallow groove, 34 ... circumferential shallow groove, CL ... tire equator, H ... tire width direction, K ... tire radius Direction, L: tread half width, M: center region, P: shoulder region, S: tire circumferential direction, TE: tread edge, W: tread width.

Claims (6)

A motorcycle tire having a main groove and a shallow groove shallower than the main groove on the tread surface,
When the tread surface between the tire equator and the tread end is equally divided into a tire equator-side center region and a tread end-side shoulder region, the center region extends in an inclined manner with respect to the tire circumferential direction. With an inclined main groove,
An inclined shallow groove having a portion extending along the inclined main groove is formed on the outer side in the tire width direction of the inclined main groove,
A tire for a motorcycle in which the length of the inclined shallow groove in the tire circumferential direction is 50 to 100% of the length of the inclined main groove in the tire circumferential direction. The motorcycle tire according to claim 1,
The center region is divided into two equal parts, an inner center region on the inner side in the tire width direction and an outer center region on the outer side in the tire width direction, and the shoulder region is divided into an inner shoulder region on the inner side in the tire width direction and an outer shoulder region on the outer side in the tire width direction. A motorcycle tire in which the negative ratio of shallow grooves in each region is the largest in the outer center region when equally divided. The motorcycle tire according to claim 1,
When the tread surface of the tread between the tire equator and the tread edge is divided equally into the first to eighth areas from the tire equator to the tread edge, the negative ratio of the shallow groove in each area is the highest in the third area. Increased motorcycle tires. The motorcycle tire according to claim 1,
When the tread surface of the tread between the tire equator and the tread edge is divided equally into the first to eighth areas from the tire equator to the tread edge, the negative ratio of the main groove in each area is the highest in the second area. Increased motorcycle tires. The motorcycle tire according to claim 1,
When the tread surface of the tread between the tire equator and the tread edge is divided equally into the first to eighth areas from the tire equator to the tread edge, the negative ratio of the shallow groove in each area is the highest in the third area. Motorcycle tires that grow and become the second largest in the eighth region. The motorcycle tire according to claim 1,
When the tread surface of the tread portion between the tire equator and the tread end is equally divided into first to eighth regions from the tire equator toward the tread end, a plurality of circumferential shallow grooves extending in the tire circumferential direction are eighth. Motorcycle tires formed in the area.

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