Motorcycle tires for off-road riding

Abstract

To provide a two-wheeler tire for traveling on irregular ground which can exhibit excellent roll characteristics.SOLUTION: A two-wheeler tire for traveling on irregular ground includes a tread part 2. The tread part 2 includes: a tire equator C; a first tread end T1; and a first block 11. Each of the plurality of first blocks 11 includes a tread 11s and an outside side wall 13. The tread 11s includes an outside edge 15. The outside edge 15 includes a projection 18, a first portion 16, and a second portion 17. The first portion 16 and the second portion 17 are arranged to form a minor angle therebetween and at the first tread end T1 side.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a two-wheeled vehicle tire for traveling on uneven terrain. [Background Art]

[0002] The following Patent Document 1 proposes a motorcycle tire for traveling on uneven terrain, which has a block pattern in which a plurality of blocks are provided in a tread portion. At least one of the blocks of the tire includes a pair of lateral narrow groove portions extending in the tire axial direction on a tread surface having a pair of lateral edges extending in the tire axial direction, and a pair of edge side pieces divided between the lateral edges and the lateral narrow groove portions. Further, in at least one of the pair of edge side pieces, the length in the tire circumferential direction increases from a narrow portion having the smallest length in the tire circumferential direction toward both sides in the tire axial direction. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2019-108037 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] The above-mentioned tire has room for improvement in roll characteristics when leaning the vehicle during turning (characteristics including agility during rolling and responsiveness during rolling).

[0005] The present invention has been devised in view of the above-described actual circumstances, and a main object thereof is to provide a two-wheeled vehicle tire for traveling on uneven terrain that can exhibit excellent roll characteristics. [Means for Solving the Problem]

[0006] The present invention relates to a two-wheeled vehicle tire for off-road riding having a tread portion, wherein the tread portion comprises a tire equator, a first tread end, and a plurality of first blocks positioned on the first tread end side of the tire equator, each of the plurality of first blocks comprising a tread surface facing outward in the radial direction of the tire and an outer side wall on the first tread end side, the tread surface including an outer edge between the tread surface and the outer side wall, the outer edge including a projection that locally protrudes toward the first tread end side, a first portion located on one side of the projection in the tire circumferential direction, and a second portion located on the other side of the projection in the tire circumferential direction, the first portion and the second portion being positioned to form a sub-angle between them and toward the first tread end side, the present invention relates to a two-wheeled vehicle tire for off-road riding. [Effects of the Invention]

[0007] The motorcycle tire for off-road driving according to the present invention can exhibit excellent roll characteristics by adopting the above configuration. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view of the tread portion of a motorcycle tire for off-road riding according to this embodiment. [Figure 2] Figure 1 is an exploded view of the tread section. [Figure 3] This is an enlarged perspective view of the first block in Figure 2. [Figure 4] This is an enlarged plan view of the first block in Figure 2. [Figure 5] This is an enlarged side view showing the first part, the second part, and the protruding part of the first block. [Figure 6] This is an enlarged plan view of the outer first block in Figure 2. [Figure 7] This is an exploded view of the tread area of ​​the tire used as an example. [Modes for carrying out the invention]

[0009] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Figure 1 shows a cross-sectional view of the tread portion 2 of a two-wheeled vehicle tire (hereinafter sometimes simply referred to as "tire") 1 for off-road driving in this embodiment, in its normal state. Figure 2 is an unfolded view of the tread portion 2 of tire 1 laid out in a plane. Figure 1 corresponds to the cross-sectional view along line AA in Figure 2.

[0010] "Normal condition" refers to the state in which, for tires with defined specifications, the tire is mounted on a standard rim, filled to the standard internal pressure, and is unloaded. For tires without defined specifications, the normal condition means the standard usage condition according to the tire's intended use, and is unloaded. In this specification, unless otherwise specified, the dimensions of each part are values ​​measured in the normal condition.

[0011] A "standard rim" is the rim defined for each tire within the standards system that the tire is based on. For example, it is the "standard rim" for JATMA, the "Design Rim" for TRA, and the "Measuring Rim" for ETRTO.

[0012] "Regular internal pressure" refers to the air pressure specified for each tire by each standard within the tire standard system, including the standard on which the tire is based. For JATMA, it is the "maximum air pressure," for TRA, it is the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES," and for ETRTO, it is the "INFLATION PRESSURE."

[0013] As shown in Figure 1, the tire 1 of this embodiment is suitably used, for example, as a tire for motocross competitions. The tire 1 of this embodiment is suitably used, for example, as a rear tire for a motocross vehicle. However, the present invention is not limited to these embodiments. In a cross-section, the tread portion 2 of the tire 1 has an outer surface that is curved in a convex arc shape outward in the radial direction of the tire.

[0014] The tire 1 of the present embodiment includes, for example, a carcass and a tread reinforcing layer (not shown). Known configurations are appropriately adopted for these.

[0015] As shown in FIG. 2, the tread portion 2 of the tire 1 of the present invention has a directional pattern in which a rotation direction R is specified. The rotation direction R is indicated, for example, by characters or symbols on the sidewall portion 3 (shown in FIG. 1). However, the present invention is not limited to such an embodiment.

[0016] The tread portion 2 is divided into, for example, a crown region Cr, a middle region Mi, and a shoulder region Sh.

[0017] The crown region Cr is a region centered on the tire equator C and having a width that is 1 / 3 of the developed tread width TWe. The shoulder region Sh is a region extending from the first tread end T1 or the second tread end T2 toward the tire equator C and having a width that is 1 / 6 of the developed tread width TWe. The middle region Mi is a region between the crown region Cr and the shoulder region Sh.

[0018] The developed tread width TWe is a distance in the tire axial direction from the first tread end T1 to the second tread end T2 when the tread portion 2 is developed on a flat plane. The first tread end T1 and the second tread end T2 mean axially outer edges, in the tire axial direction, of blocks included in the block row positioned most outward in the tire axial direction among the blocks arranged on the tread portion 2. In FIG. 2, the first tread end T1 is shown as the left tread end and the second tread end T2 is shown as the right tread end, but the present invention is not limited to such an embodiment.

[0019] The tread portion 2 includes a base surface 4 and a plurality of blocks 5 protruding outward from the base surface 4 in the tire radial direction. The tread surface facing outward in the tire radial direction of each block 5 extends parallel to the base surface 4. The blocks 5 according to the present embodiment include a plurality of crown blocks 6 on the tire equator C side, a plurality of shoulder blocks 8 on the first tread end T1 or second tread end T2 side, and a plurality of middle blocks 7 disposed between these blocks. In the crown block 6, the centroid of the outer tread surface in the tire radial direction (which means the contact surface when the tire is run on a flat surface, the same applies hereinafter) is located within the crown region Cr. In the middle block 7, the centroid of the tread surface is located within the middle region Mi. In the shoulder block 8, the centroid of the tread surface is located within the shoulder region Sh. When a groove is provided in the tread surface, the centroid means the centroid of the tread surface in a state where all grooves are filled.

[0020] The tread portion 2 of the present invention includes a plurality of first blocks 11 disposed closer to the first tread end T1 than the tire equator C. The first block 11 of the present embodiment is configured as the middle block 7 disposed in the middle region Mi, but the first block 11 may be disposed in the shoulder region Sh.

[0021] The first blocks 11 according to the present embodiment include, for example, a plurality of inner first blocks 11A disposed relatively on the tire equator C side, and a plurality of outer first blocks 11B disposed closer to the first tread end T1 than these inner first blocks. The inner first blocks 11A are entirely disposed within the middle region Mi, whereas the outer first blocks 11B are disposed so as to straddle the middle region Mi and the shoulder region Sh. In a preferred embodiment, the inner first blocks 11A and the outer first blocks 11B are provided alternately in the tire circumferential direction. However, the present invention is not limited to such an embodiment. Hereinafter, the configuration of the first block 11 will be described mainly by taking the inner first block 11A as an example.

[0022] Figure 3 shows an enlarged perspective view of the first block 11, and Figure 4 shows an enlarged plan view of the first block 11. In this specification, in enlarged plan views showing the treads of blocks, such as the one shown in Figure 4, the outline of the treads of the blocks is clearly shown, while the side and base structures of the blocks may be omitted, even if they can be observed in the plan view of the blocks.

[0023] As shown in Figures 3 and 4, each of the plurality of first blocks 11 comprises a tread surface 11s facing outward in the radial direction of the tire and an outer side wall 13 on the first tread end T1 side. The tread surface 11s also includes an outer edge 15 between the tread surface 11s and the outer side wall 13. The outer edge 15 is conceived as a ridge line formed between the tread surface 11s and the outer side wall 13. When the tread surface 11s and the outer side wall 13 connect to form a small curved surface, the outer edge 15 is conceived as a set of center positions of arcs observed in the cross-section of the curved surface.

[0024] As shown in Figure 3, the outer edge 15 includes a projection 18 and a first portion 16 and a second portion 17. The projection 18 protrudes locally toward the first tread end T1. The first portion 16 is located on one side of the projection 18 in the tire circumferential direction. The second portion 17 is located on the other side of the projection 18 in the tire circumferential direction.

[0025] As shown in Figure 4, the first portion 16 and the second portion 17 are positioned to form a suboptimal angle between them and on the first tread edge T1 side. That is, of the conjugate angles formed by the first portion 16 and the second portion 17 on the tire equator C side and the conjugate angles on the first tread edge T1 side, the conjugate angle on the first tread edge T1 side is less than 180°. By adopting the above configuration, the tire 1 of the present invention can exhibit excellent roll characteristics.

[0026] Roll characteristics refer to the overall impression a driver may feel when rolling a vehicle during a turn. Therefore, roll characteristics include at least the agility during rolling and the responsiveness during rolling. Agility during rolling means that the vehicle can be rolled with less force. Response during rolling means that the driver receives an appropriate reaction force from the vehicle during rolling, and that this reaction force is linear. "Excellent roll characteristics" means that these characteristics are well-balanced, and therefore excellent results can be expected in motocross competitions and the like.

[0027] The reason why the tire 1 of the present invention can exhibit excellent roll characteristics is as follows. In the present invention, the tread surface 11s of the first block 11 includes a protrusion 18, which suppresses deformation of the first block 11 during rolling (deformation such that the block excessively leans towards the first tread edge). As a result, the driver can get sufficient feedback during rolling. On the other hand, in the tire 1 of the present invention, the first portion 16 and the second portion 17 of the outer edge 15 are arranged to form a negative angle between them and toward the first tread edge T1. As a result, when the outer edge 15 makes contact with the ground during turning, the outer edge 15 and the outer side wall 13 deform appropriately so that the negative angle increases. This action helps to improve agility during rolling, and in combination with the above effect of the protrusion 18, excellent roll characteristics are obtained.

[0028] The configuration of this embodiment will be described in more detail below. The configuration described below represents a specific aspect of this embodiment. Therefore, it goes without saying that the present invention can achieve the above-described effects even without the configuration described below. Furthermore, even if any one of the configurations described below is applied individually to a tire of the present invention having the above-described features, an improvement in performance corresponding to each configuration can be expected. Moreover, if several of the configurations described below are applied in combination, a combined improvement in performance corresponding to each configuration can be expected.

[0029] As shown in Figure 3, the first portion 16, the second portion 17, and the projection 18 extend in a straight line. The outer side wall 13 of this embodiment also includes a planar first side wall portion 21, a second side wall portion 22, and a projection side wall 23 that are connected to these edges. The first side wall portion 21 extends from the first portion 16 toward the base of the first block 11. The second side wall portion 22 extends from the second portion 17 toward the base. The projection side wall 23 extends from the projection 18 toward the base of the first block 11. The outer side wall 13 of this embodiment has a shape that is recessed toward the tire equator C by the first side wall portion 21 and the second side wall portion 22. In addition, the projection side wall 23 protrudes locally from the bottom portion of the outer side wall 13.

[0030] As shown in Figure 4, the tread surface 11s of the first block 11 in this embodiment is provided with a single narrow groove 25. This narrow groove 25 is semi-annular, with both ends opening at the outer side walls 13. The first block 11 also includes a protruding block piece 26 surrounded by the narrow groove 25. In this embodiment, this protruding block piece 26 includes a protruding portion 18. However, the present invention is not limited to this embodiment. That is, even if the narrow groove 25 and the protruding block piece 26 are not present, the above-described effects can be expected as long as the tread surface 11s includes the first portion 16, the second portion 17 and the protruding portion 18 described above.

[0031] In a plan view of the tread surface 11s, the protrusion 18 protrudes 1 mm or more outward in the block width direction from the first portion 16 and the second portion 17. That is, the distance L1 in the tire axial direction from the end of the first portion 16 or the second portion 17 on the protrusion 18 side to the end of the protrusion 18 on the first tread end T1 side is 1 mm or more. In a preferred embodiment, the distance L1 is 1.0 to 3.0 mm. This makes the area around the protrusion 18 more easily deformable, and for example, when driving on a muddy road surface, mud and soil adhering to the periphery of the first block 11 can be effectively discharged.

[0032] The maximum length L3 of the protruding sidewall 23 in the tire circumferential direction is, for example, 5% to 75% of the maximum length L2 of the tread surface 11s of the first block 11 in the tire circumferential direction. In a preferred embodiment, the length L3 of the protruding sidewall 23 is 5% to 25% of the length L2 of the tread surface 11s of the first block 11, and more preferably 5% to 15%. This allows the protruding block piece 26 to have appropriate rigidity and exert a large reaction force in the tire circumferential direction, thereby improving traction performance.

[0033] As shown in Figure 2, the sub-angle θ1 between the first part 16 and the second part 17 is, for example, 140 to 160°. This ensures that the above-mentioned effect is obtained.

[0034] Figure 5 shows an enlarged side view of the first block 11 (the side view observed in the direction of arrow B in Figure 2) showing the first part 16, the second part 17, and the projection 18. As shown in Figure 5, the projection 18 includes a portion that protrudes in the height direction of the first block 11 more than the first part 16 and the second part 17. In a preferred embodiment, the entire projection 18 protrudes in the height direction more than the first part 16 and the second part 17. In a more preferred embodiment, the entire tread surface 26s of the projection block piece 26 protrudes in the height direction more than the other portions. The maximum height h1 measured at the projection 18 of the first block 11 is 102% to 120% of the maximum height h2 measured at the first part 16 or the second part 17 of the first block 11. In this embodiment, the height relationship between the protruding portion 18 and the first portion 16 or the second portion 17 is applied to the relationship between the height measured on the tread surface 26s of the protruding block piece 26 and the height measured on the other portion of the tread surface 11s. Such a first block 11 improves roll characteristics while the protruding block piece 26 provides greater grip, thereby improving traction performance and cornering performance.

[0035] As shown in Figure 4, the tread surface 26s of the protruding block piece 26 includes a fixed-width portion 31 that extends toward the tire equator with the same width as the length of the protrusion 18, and a widened portion 32 whose width in the tire circumferential direction increases toward the tire equator C. In this embodiment, in a plan view of the tread surface 11s of the first block 11, the entire widened portion 32 is surrounded by the narrow groove 25. Also, in the plan view, most of the fixed-width portion 31 (more than 80% of the area of ​​the fixed-width portion 31) is located toward the first tread edge T1 than the imaginary line (not shown) connecting the end of the first portion 16 toward the protrusion 18 and the end of the second portion 17 toward the protrusion 18. A protruding block piece 26 having such a tread surface 26s can enhance traction performance by having the edge of the fixed-width portion 31 provide grip in the tire circumferential direction.

[0036] The area of ​​the widened section 32 is preferably larger than the area of ​​the fixed-width section 31. For example, the area of ​​the widened section 32 is 3.0 to 4.0 times the area of ​​the fixed-width section 31. This effectively suppresses damage to the protruding block piece 26.

[0037] The widened portion 32 includes two linearly extending edges 32e. These two edges 32e extend non-parallel to each other. The angle θ2 between these two edges 32e is, for example, 20 to 40°, preferably 25 to 35°. Such a widened portion 32 can prevent excessive leaning of the protruding block piece 26 toward the first tread end T1, thereby improving the feel during rolling.

[0038] The narrow groove 25 includes two transverse grooves 35 and one longitudinal groove 36. Each of the two transverse grooves 35 extends from the outer side wall 13 toward the tire equator C. The longitudinal groove 36 extends from the end of one transverse groove 35 toward the tire equator C to the end of the other transverse groove 35 toward the tire equator C. The transverse grooves 35 and the longitudinal groove 36 each extend in a straight line. The transverse grooves 35 and the longitudinal groove 36 are connected in such a way that they form an acute angle.

[0039] The two lateral grooves 35 extend inclined toward the tire equator C, moving away from each other. The angle between the two lateral grooves 35 is substantially the same as the angle θ2 between the two edges 32e of the widening section 32.

[0040] The longitudinal groove 36 is preferably located in the central part of the first block 11. From this viewpoint, in this embodiment, at least a portion of the longitudinal groove 36 is located in the central region when the tread surface 11s with the narrow groove 25 filled is divided into three regions with equal area by two imaginary straight lines extending parallel to the circumferential direction of the tire. In a more preferred embodiment, the entire longitudinal groove 36 is located in the central region. Such arrangement of the longitudinal groove 36 helps to suppress uneven wear of the first block 11.

[0041] The maximum groove width W1 of the narrow groove 25 should preferably be 70% to 90% of the maximum length L3 of the protruding side wall 23 in the tire's circumferential direction. Such narrow grooves 25 help to suppress uneven wear of the blocks while improving grip performance on muddy surfaces.

[0042] The first block 11 includes an inner side wall 14 on the tire equator C side. The inner side wall 14 is preferably concave toward the first tread end T1 side. Specifically, the tread surface 11s includes an inner edge 20 between the tread surface 11s and the inner side wall 14, and this inner edge 20 is composed of two straight edges arranged to form a lower angle toward the tire equator C side. The inner side wall 14 also includes two planes (not shown) extending from the two straight edges to the base of the first block 11. Such an inner side wall 14 can provide a large reaction force in the tire axial direction, especially when turning on muddy surfaces, thereby improving turning performance.

[0043] In a desirable embodiment, the inferior angle θ3 formed by the inner edge 20 is greater than the inferior angle θ1 (shown in Figure 2) between the first portion 16 and the second portion 17 of the outer edge 15. Specifically, the inferior angle θ3 is 150 to 170°. This results in a more linear change in feel during rolling, further improving the rolling characteristics.

[0044] Figure 6 shows an enlarged plan view of the outer first block 11B. As shown in Figure 6, the features of the first block 11 (inner first block 11A) described above can be applied to the outer first block 11B.

[0045] The outer first block 11B is formed in a more elongated shape in the tire circumferential direction compared to the inner first block 11A. Therefore, the aspect ratio obtained by dividing the maximum length of the tread surface 11s in the tire circumferential direction by the maximum length of the tread surface 11s in the tire axial direction is greater for the outer first block 11B than for the inner first block 11A. Specifically, the aspect ratio of the inner first block 11A is 1.25 to 1.40, while the aspect ratio of the outer first block 11B is 1.40 to 1.50. As a result, the outer first block 11B can provide a larger reaction force in the tire axial direction, improving cornering performance.

[0046] As shown in Figure 2, it is desirable that the angle θ4 of the inferior angle between the first portion 16 and the second portion 17 of the outer edge 15 of the outer first block 11B be greater than the angle θ1 of the inner first block 11A. Specifically, the angle θ4 is set to 165-170°, and the difference between the angle θ4 and the angle θ1 is set to 10-25°. This allows for excellent roll characteristics in various road surface conditions.

[0047] From a similar viewpoint, as shown in Figure 6, it is desirable that the inferior angle θ5 formed by the inner edge 20 of the outer first block 11B is greater than the inferior angle θ3 (shown in Figure 4) formed by the inner edge 20 of the inner first block 11A. Specifically, the angle θ5 is set to 165-175°, and the difference between the angle θ3 and the angle θ5 is set to 5-10°.

[0048] As shown in Figure 2, the crown region Cr is provided with, for example, multiple crown blocks 6. In this embodiment, first crown blocks 6A and second crown blocks 6B of different shapes are alternately provided in the circumferential direction of the tire.

[0049] The first crown block 6A has a substantially rectangular tread surface, and this tread surface does not have grooves. On the other hand, the second crown block 6B includes two block pieces 41 and a tie bar 42 connecting them. However, the crown block 6 is not limited to this embodiment.

[0050] In a plan view of the tread section 2, it is desirable that a virtual region 43 extending the inner first block 11A parallel to the tire axis direction toward the tire equator C overlaps with at least a portion of the first crown block 6A. Similarly, it is desirable that a virtual region 44 extending the outer first block 11B parallel to the tire axis direction toward the tire equator C overlaps with at least a portion of the second crown block 6B. Such a block arrangement helps to improve traction performance by allowing the crown block 6 and the first block 11 to work together to provide a large reaction force in the circumferential direction of the tire when driving on a muddy surface.

[0051] Multiple shoulder blocks 8 are provided in the shoulder region Sh. In this embodiment, in a plan view of the tread portion 2, the first block 11 (including both the inner first block 11A and the outer first block 11B) is parallel to the tire axis direction. First tread end T1 The extended virtual region 45 does not overlap with the shoulder block 8. This block arrangement makes it difficult for soil and mud to accumulate between the first block 11 and the shoulder block 8, allowing for the sustained performance of excellent rolling characteristics.

[0052] The tread portion 2 of this embodiment includes a plurality of second blocks 12 positioned on the second tread end T2 side of the tire equator C. These second blocks 12 have substantially the same characteristics as the first block 11 described above.

[0053] Although preferred embodiments of the motorcycle tire for off-road riding according to the present invention have been described in detail above, the present invention is not limited to the specific embodiments described above and can be implemented in various modified forms. [Examples]

[0054] A prototype rear tire for a motorcycle designed for off-road riding was fabricated, having the basic pattern shown in Figure 2. As a comparative example, a prototype tire with the tread pattern shown in Figure 7 was fabricated. As shown in Figure 7, the comparative example tire is based on the tread pattern shown in Figure 2, but with block a, which does not possess the features of the present invention, replacing the first and second blocks. Except for the above, the comparative example tire is substantially the same as the example tire. The roll characteristics of these test tires were tested. The common specifications and test methods for each test tire are as follows. Vehicle used: 450cc motocross competition vehicle Tire size: 120 / 80-19 Rim size: 2.15WM Internal pressure: 80kPa The testing method is as follows:

[0055] <Role characteristics> The roll characteristics of the above test vehicle when driven on a motocross course were evaluated subjectively by the test rider. The roll characteristics were the sum of scores for roll agility and roll response, and these items were evaluated on a 5-point scale. A higher score indicates better performance in each category. The test results are shown in Table 1.

[0056] [Table 1]

[0057] As shown in Table 1, the tires in the examples were confirmed to exhibit excellent roll characteristics.

[0058] [Note] The present invention includes the following embodiments.

[0059] [Invention 1] A motorcycle tire for off-road riding having a tread section, The tread portion comprises a tire equator, a first tread end, and a plurality of first blocks positioned on the first tread end side of the tire equator. Each of the plurality of first blocks comprises a tread surface facing outward in the radial direction of the tire and an outer side wall on the end side of the first tread, The tread surface includes the outer edge between the tread surface and the outer side wall, The outer edge includes a projection that protrudes locally toward the first tread end, a first portion located on one side of the projection in the tire circumferential direction, and a second portion located on the other side of the projection in the tire circumferential direction. The first portion and the second portion are arranged to form a lower angle between them and toward the first tread end. Motorcycle tires designed for off-road riding. [2nd Invention] In a plan view of the tread surface, the protruding portion protrudes 1 mm or more outward in the block width direction from the first portion and the second portion, as described in Invention 1, for a two-wheeled vehicle for off-road driving. [Invention 3] The outer side wall includes a protruding side wall extending from the protrusion toward the base of the first block, The maximum length of the protruding side wall in the tire circumferential direction is 5% to 75% of the maximum length of the tread surface of the first block in the tire circumferential direction, as described in invention 1 or 2 for a motorcycle tire for off-road driving. [4th Invention] The aforementioned protruding portion includes a portion that protrudes more than the first portion and the second portion in the height direction of the first block, wherein this is a two-wheeled vehicle tire for off-road driving according to any one of claims 1 to 3 of the present invention. [5th ​​Invention] The tire for a motorcycle for off-road riding according to the present invention, wherein the maximum height measured at the protruding portion of the first block is 102% to 120% of the maximum height measured at the first or second portion of the first block. [Invention 6] The aforementioned tread surface is provided with a single narrow groove. The aforementioned narrow groove is semi-annular, with both ends opening at the outer side wall. The first block includes the protruding portion and the protruding block piece surrounded by the narrow groove, the tire for a two-wheeled vehicle for off-road driving according to any one of claims 1 to 5 of the present invention. [7th Invention] The aforementioned first block is on the equator side of the tire. Inner side wall Includes, The aforementioned Inner side wall The tire for a motorcycle for off-road riding according to any one of claims 1 to 6 of the present invention is recessed toward the first tread end. [Explanation of Symbols]

[0060] 2 Tread section 11. Block 1 11s tread 13 Outer side wall 15 Outer edge 16 Part 1 17 Part 2 18 Protrusion T1 First tread end C Tire Equator

Claims

1. A motorcycle tire for off-road riding having a tread section, The tread portion comprises a tire equator, a first tread end, and a plurality of first blocks arranged on the first tread end side of the tire equator. Each of the plurality of first blocks comprises a tread surface facing outward in the radial direction of the tire and an outer side wall on the end side of the first tread, The tread surface includes the outer edge between the tread surface and the outer side wall, The outer edge includes a projection that protrudes locally toward the first tread end, a first portion located on one side of the projection in the tire circumferential direction, and a second portion located on the other side of the projection in the tire circumferential direction. The first portion and the second portion are arranged to form a lower angle between them and on the first tread end side, The aforementioned tread surface is provided with a single narrow groove. The aforementioned narrow groove is semi-annular, with both ends opening at the outer side wall. The first block includes the protruding portion and includes the protruding block piece surrounded by the narrow groove, The tread surface of the protruding block piece includes a fixed-width portion that extends toward the tire equator with the same width as the length of the protruding portion, and a widened portion whose width in the tire circumferential direction increases toward the tire equator. Motorcycle tires designed for off-road riding.

2. In a plan view of the tread surface, the protruding portion protrudes 1 mm or more outward in the block width direction from the first portion and the second portion, as described in claim 1 for a motorcycle tire for off-road driving.

3. The outer side wall includes a protruding side wall extending from the protruding portion toward the base of the first block, The tire for a motorcycle for off-road riding according to claim 1 or 2, wherein the maximum length of the protruding side wall in the tire circumferential direction is 5% to 75% of the maximum length of the tread surface of the first block in the tire circumferential direction.

4. The tire for a motorcycle for off-road riding according to claim 1 or 2, wherein the protruding portion includes a portion that protrudes more than the first portion and the second portion in the height direction of the first block.

5. The tire for a motorcycle for off-road riding according to claim 4, wherein the maximum height measured at the protruding portion of the first block is 102% to 120% of the maximum height measured at the first or second portion of the first block.

6. The first block includes an inner side wall on the tire equator side, The inner side wall is recessed toward the first tread end, the tire for a motorcycle for off-road riding according to claim 1 or 2.

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