JP4643675B2 - Pneumatic tire for motorcycle and manufacturing method thereof - Google Patents

Description

  The present invention relates to a pneumatic tire for a motorcycle and a manufacturing method thereof.

A tread of a conventional pneumatic tire is formed by winding one piece of a wide band-shaped tread rubber substantially equal to the tread width of a finished tire around the outer periphery of a belt layer or the like attached to a crown portion of a carcass ply. Band-wound tread (see, for example, Patent Document 1), and spiral tread in which band-shaped rubber is spirally wound around the outer periphery of the belt layer or the like (over substantially the entire tread width of the finished tire) (Patent Document 2 and Patent Document 3) Reference) and a width-direction divided tread (see Patent Document 4 and Patent Document 5).
JP-A-9-239865 Japanese Patent Laid-Open No. 10-323917 JP-A-11-320706 JP-A-4-146121 Japanese Patent Laid-Open No. 4-146122

  However, the pneumatic tire for motorcycles has a much larger tread drop rate than the tire for passenger cars, and the outer diameter is significantly different between the tread center and the tread end in the tire axial direction. The difference is big. For this reason, in the above-described band-wound tread, the tread end portion is greatly squeezed during vulcanization molding due to the circumferential length difference between the tread center portion and the tread end portion, and the tread rubber tends to bend or overlap at the tread end portion. As a result, there has been a problem that the tread thickness is not uniform in the tire circumferential direction.

  When the tread thickness is not uniform, there is a problem that the uniformity of the product tire is deteriorated to cause vibration and jumping, and minute vibration called chattering during actual vehicle driving is deteriorated.

  On the other hand, in the spiral tread, although the non-uniformity of the thickness due to the wrinkle at the end of the tread is improved, there is a problem that the manufacturing time becomes long due to the spiral winding.

  In particular, in the case of a spiral tread that uses two or more types of rubbers that are different at the center portion of the tread and both sides thereof, such as a width-direction divided tread, it is necessary to change the rubber type, which further increases the manufacturing time. . In order to make it unnecessary to switch the rubber type, it is conceivable to use a raw ribbon tread rubber extrusion device directly connected to a molding machine, but this device must be prepared by the number of rubber types, which increases costs. There is a problem.

  In consideration of the above facts, the present invention aims to improve uniformity, wear resistance and durability while minimizing the manufacturing cost in a pneumatic tire for a motorcycle having a large tread drop rate. To do.

  The invention according to claim 1 is provided on an outer peripheral surface of a band assembly including at least a pair of bead cores, a carcass ply straddling one bead core and the other bead core, and a belt layer provided on the outer peripheral surface of the carcass ply. A method for manufacturing a pneumatic tire for a motorcycle, wherein a raw tire is formed by pasting a vulcanized tread rubber member, and the raw tire is vulcanized using a mold for vulcanization. It is divided into end regions, and as the tread rubber member of at least the tread surface side outermost layer of the end regions, unvulcanized belt-like rubber is spirally wound in the tire circumferential direction and from the outer side in the tire axial direction toward the inner side As the tread rubber member of at least the tread surface side outermost layer in the central region, unvulcanized band-shaped rubber having a width wider than that of the unvulcanized belt-shaped rubber It is characterized by winding one turn in the tire circumferential direction.

  In the method for manufacturing a pneumatic tire for a motorcycle according to claim 1, as a tread rubber member of at least the tread side outermost layer in the end region of the tread, unvulcanized belt-like rubber is wound spirally in the tire circumferential direction ( Therefore, the manufacturing time (wrapping time of the belt-like rubber) is shorter than that of the spiral tread over the entire width of the tread, and an increase in manufacturing cost can be suppressed.

  In addition, the tread thickness is made uniform because there is no wrinkle of the tread rubber due to narrowing at the time of molding the tire at the end of the tread where the drop rate is large. Further, since the unvulcanized belt-like rubber is lap-wrapped from the outer side to the inner side in the tire axial direction, even if stress is applied from the central region to the end region of the tread during running of the camber, the belt-like rubber is not yet vulcanized. The uneven wear performance of the pneumatic tire can be improved so that no wrinkle-like uneven wear occurs at the end of the raised portion. Further, as the tread rubber member in the central region having a lower drop rate than the end region of the tread, the unvulcanized band-shaped rubber is wound once in the tire circumferential direction (referred to as a band-wound tread). The manufacturing time can be shortened as compared with the case of using a spiral tread, and an increase in manufacturing cost is suppressed.

  Therefore, according to the method for manufacturing a pneumatic tire for a motorcycle according to claim 1, it is possible to manufacture a pneumatic tire for a motorcycle excellent in uniformity, wear resistance, and durability over the entire tread.

  Invention of Claim 2 is the manufacturing method of the pneumatic tire for motorcycles of Claim 1, The distance from the tire equatorial plane in the tire axial direction of the said tread to the boundary surface of the said center area | region and the said edge part area | region However, the tread rubber member is attached so as to gradually increase outward in the tire radial direction.

  In the method for manufacturing a pneumatic tire for a motorcycle according to claim 2, the tread rubber member is pasted so that the distance to the boundary surface between the central region and the end region gradually increases outward in the tire radial direction. Therefore, even if stress is applied from the central region to the end region of the tread during camber travel, no backspread or open splice is likely to occur at the boundary surface between the central region and the end region, and the durability is high.

  Note that the open splice is a peeling phenomenon along the joining interface that occurs when the joining interface between rubber and rubber, such as a joining interface between the same type of rubbers or a joining interface of different types of rubber, is subjected to repeated stress. .

  According to a third aspect of the present invention, in the method for manufacturing a pneumatic tire for a motorcycle according to the first or second aspect, a strip formed by rubber-covering at least one cord as the belt layer is provided in the tire circumferential direction. It is characterized by being spirally wound.

  The method for manufacturing a pneumatic tire for a motorcycle according to claim 3, wherein the belt layer is a spiral belt, and the tread end portion during vulcanization molding even when there is a large circumferential length difference in the tire case before tread application As a result, the tread thickness is made uniform.

  In addition, by using a spiral belt as the belt layer, the carcass ply is reinforced more strongly and higher high-speed durability can be obtained.

  According to a fourth aspect of the present invention, in the method for manufacturing a pneumatic tire for a motorcycle according to any one of the first to third aspects, the central region is assembled with a finished tire on a regular rim and filled with a regular internal pressure. In a no-load state, when the distance in the tire axial direction from the tire equator surface is x, and the distance in the tire radial direction from the tread surface at the position of the distance x to the tread surface at the tire equator surface is y The falling rate (y / x × 100) is a region having a maximum of 10 to 35%, and the end region is a region on the both sides of the tire equatorial plane that is more outward in the tire axial direction than the central region. It is a feature.

  Here, “regular rim” refers to a standard rim in the applicable size specified in the 2004 version YEAR BOOK issued by JATMA, and “normal load” and “regular internal pressure” are similarly issued by JATMA. This refers to the maximum load and the air pressure for the maximum load in the applicable size and ply rating defined in the 2004 YEAR BOOK.

  When the TRA standard or ETRTO standard is applied at the place of use or manufacturing, the respective standards are followed.

  In the method for manufacturing a pneumatic tire for a motorcycle according to claim 4, since the center region and the end region are appropriately defined by the drop rate, wrinkles and the like at the tread end during vulcanization molding are suppressed. The tread thickness is made uniform. For this reason, uniformity is good.

  In addition, in the case where a wide band-shaped rubber is wound around the central region, the winding time of the tread rubber member is shortened, so that the manufacturing cost can be suppressed.

  According to a fifth aspect of the present invention, there is provided at least one layer of a carcass ply wound around a bead core disposed between the pair of bead portions in a toroidal shape from the inside to the outside, and positioned radially outward of the carcass ply. A pneumatic tire for a motorcycle having at least one belt layer and a tread located radially outward of the belt layer, the tread being divided into a central region and an end region, At least the tread side outermost layer in the end region is a spiral tread in which an unvulcanized belt-like rubber is spirally wound in the tire circumferential direction and is lap-wrapped from the outer side to the inner side in the tire axial direction and vulcanized. And at least the outermost layer on the tread surface side of the central region is wound with one round of unvulcanized band-shaped rubber that is wider than the band-shaped rubber in the tire circumferential direction. It is characterized by a band wound tread formed by vulcanization molding.

  In the pneumatic tire for a motorcycle according to claim 5, since at least the outermost layer on the tread side in the end region of the tread is a spiral tread, the manufacturing time is longer than the spiral tread over the entire width of the tread. The tread thickness is uniform because there is no wrinkle of the tread rubber due to narrowing at the time of molding the tire at the end of the tread where the time is short, the manufacturing cost can be suppressed, and the drop rate is large.

  Therefore, in the pneumatic tire for a motorcycle according to claim 5, the uniformity is good and chattering does not occur when the vehicle travels. Further, by adopting the spiral tread in the end region, the wear resistance and durability in the end region are improved. In addition, since this uncured rubber band is rolled up from the outside in the tire axial direction to the inside, this spiral tread is stressed from the central region to the end region of the tread when running camber frequently used in two-wheeled vehicles. Even in this case, it is difficult for the side-shaped uneven wear to occur at the end of the band-shaped rubber before vulcanization, and the uneven wear performance is high. Furthermore, by making the central region having a lower drop rate compared to the end region of the tread a single-band band-wound tread, the manufacturing time is shortened compared to the case where the central region is a spiral tread, and the manufacturing cost is reduced. It is suppressed. Therefore, in the pneumatic tire for a motorcycle according to claim 5, an increase in cost can be suppressed, and uniformity, wear resistance, and durability can be improved over the entire tread.

  A sixth aspect of the present invention is the pneumatic tire for a motorcycle according to the fifth aspect, wherein a distance from the tire equator plane in the tire axial direction to a boundary surface between the central region and the end region is a tire radial direction. The boundary surface is inclined in a tire radial direction cross section so as to gradually increase outward.

  The pneumatic tire for a motorcycle according to claim 6, wherein the boundary surface is a tire radial cross section so that the distance to the boundary surface between the center region and the end region gradually increases outward in the tire radial direction. Therefore, even if a stress is applied from the central region to the end region of the tread during the camber traveling, the interface between the central region and the end region is unlikely to be crushed and open splices are generated, and the durability is high.

  According to a seventh aspect of the present invention, in the pneumatic tire for a motorcycle according to the fifth or sixth aspect, the belt layer has a strip formed by rubber-coating at least one cord in a spiral shape in the tire circumferential direction. It is characterized by being a spiral belt that is wound.

  When the belt layer is a spiral belt, since the expansion rate of the tire case at the time of vulcanization cannot be increased, the tire case before the tread is almost preliminarily shaped close to the product. For this reason, there is a large diameter difference (circumferential length difference) between the tire axial direction center region and the end region of the tire case, and it is necessary to affix a tread rubber on the tire case.

  The pneumatic tire for a motorcycle according to claim 7, wherein the belt layer is a spiral belt, and even when there is a large circumferential length difference in the tire case before the tread is pasted, the wrinkles near the end of the tread during vulcanization molding Etc. are suppressed, so that the tread thickness is made uniform.

  In addition, by using a spiral belt as the belt layer, the carcass ply is reinforced more strongly and higher high-speed durability can be obtained.

  The invention according to claim 8 is the pneumatic tire for a motorcycle according to any one of claims 5 to 7, wherein the central region is assembled to a normal rim, is filled with a normal internal pressure, and is in an unloaded state. Where x is the distance in the tire axial direction from the tire equator plane, and y is the distance in the tire radial direction from the tread tread surface at the position of the distance x to the tread tread surface at the tire equator plane. xx100) is a region having a maximum of 10 to 35%, and the end region is a region on the both sides of the tire equatorial plane that is more outward in the tire axial direction than the central region.

  In the pneumatic tire for a motorcycle according to claim 8, since the center region and the end region are appropriately defined by the drop rate, wrinkles and the like at the tread end during vulcanization molding are suppressed, and the tread thickness Is made uniform. For this reason, uniformity is good.

  In addition to this, when the central region is a band-wound tread, the winding time of the tread rubber member is shortened, and thus the manufacturing cost is suppressed.

  As described above, according to the pneumatic tire for a motorcycle of the present invention, in a pneumatic tire for a motorcycle having a large tread drop rate, the uniformity, wear resistance and durability can be reduced while minimizing the manufacturing cost. It has the outstanding effect that it can improve property.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
In FIG. 1, a pneumatic tire 100 for a motorcycle according to the present embodiment includes at least one layer wound around a bead core 14 disposed in a toroid shape between a pair of bead portions 12 and wound around from the inside to the outside. The carcass ply 16 (two layers in the illustrated example), at least one (three in the illustrated example) belt layer 18 positioned radially outward of the carcass ply 16, and the radial direction of the belt layer 18 And a tread 20 located outward.

  The belt layer 18 is a spiral belt in which a strip (not shown) formed by covering at least one cord with a rubber is spirally wound in the tire circumferential direction.

  Here, it is assembled to the regular rim, filled with regular internal pressure, and in the unloaded state, the distance in the tire axial direction from the tire equatorial plane CL is x, from the tread tread at the position of the distance x to the tread tread on the tire equatorial plane CL. Let y be the distance in the tire radial direction. A region where the drop rate (y / x × 100), which is the ratio of the distance y to the distance x, is 10 to 35% at maximum is defined as the central region 20A of the tread 20 and is more on both sides of the tire equatorial plane CL than the central region 20A. A region on the outer side in the tire axial direction is an end region 20B of the tread 20.

  In the end region 20B, the tread 20 is a spiral tread. The spiral tread is formed by unwrapping unvulcanized belt-like rubber 22 in a spiral shape so as to cover the belt layer 18 in the tire circumferential direction and on both sides of the tire equatorial plane CL from the outside in the tire axial direction to the inside. And is formed as a tread by a vulcanization mold.

  In addition, as FIG. 1 shows, the edge part area | region 20B is comprised so that it may reach to a tire maximum width position. This is because the tread 20 can come into contact with the road surface even when traveling at a large camber angle.

  A central region 20A of the tread 20 is a band-wound tread. The band-wound tread is formed by winding, for example, one turn of an unvulcanized band-shaped rubber 26 wider than the band-shaped rubber 22 in the tire circumferential direction, and is formed as a tread by a vulcanization mold.

  The boundary surface 20C between the center region 20A and the end region 20B has a tire radial cross section so that the distance from the tire equatorial surface CL to the boundary surface 20C in the tire axial direction gradually increases outward in the tire radial direction. Is inclined (inverted C in FIG. 1).

The configuration of the pneumatic tire 100 for a motorcycle according to the present embodiment is such that the distance from the tire equatorial plane CL to the tread maximum width position is a distance from the tread tread on the tire equatorial plane CL to the tread tread at the maximum tread width position. The end drop rate (Y / X × 100), which is the ratio of the tire radial direction distance Y, is as large as 50 to 95%, and is suitable for tires with a large tread end narrowing during vulcanization molding.
(Function)
Since the pneumatic tire 100 for a motorcycle uses the end region 20B of the tread 20 as a spiral tread, the manufacturing time (the winding time of the belt-like rubber 22) is shorter than the spiral tread over the entire width of the tread 20, and the manufacturing cost is reduced. In the tread end where the drop rate is large, there is no wrinkle of the tread rubber due to narrowing during tire molding, and the tread thickness is made uniform.

  Therefore, in the pneumatic tire 100 for a motorcycle according to the present embodiment, the uniformity is good and chattering does not occur during actual vehicle travel. Further, by adopting the spiral tread in the end region 20B, the wear resistance and durability in the end region 20B are improved.

  Further, by using the band-wound tread with the central region 20A having a smaller drop rate compared to the end region 20B of the tread, the manufacturing time is shortened and the manufacturing cost is suppressed as compared with the case where the central region 20A is a spiral tread. Is done.

  Therefore, the pneumatic tire 100 for a motorcycle can also suppress an increase in cost in this respect, and can improve uniformity, wear resistance, and durability over the entire tread 20.

  As shown in FIG. 2, in the end region 20 </ b> B, the belt-like rubber 22 is spirally wound from the outer side in the tire axial direction toward the inner side. Therefore, when the camber travels frequently used in two-wheeled vehicles, For example, even if a stress acts in the direction of arrow F on the end region 20B due to friction, the end 22A of the portion that was the belt-like rubber 22 before vulcanization does not face the direction of the stress and follows the stress. Therefore, it is difficult for wrinkle-like uneven wear to occur at the end portion, and the uneven wear performance is high.

  Further, the boundary surface 20C between the center region 20A and the end region 20B is inclined in the tire radial cross section so that the distance from the tire equator surface CL to the boundary surface 20C gradually increases outward in the tire radial direction. Therefore, as shown in FIG. 2, even when the camber travels, when the stress acts on the boundary surface 20C in the direction of arrow F due to friction with the road surface 28, the boundary surface 20C follows the direction of the stress. Since it is in a state, the interface 20C is unlikely to cause a backlash or an open splice, and has high durability.

  When the belt layer 18 is a spiral belt, the tire case (not shown) during vulcanization cannot have a large expansion rate. Therefore, the tire case before the tread application is formed in a shape almost similar to the product in advance. For this reason, there is a large diameter difference (circumferential length difference) between the tire axial direction center region and the end region of the tire case, and tread rubber is pasted on the tire case.

  However, in the pneumatic tire 100 for a motorcycle, even when there is a large circumferential length difference in the tire case before tread application, the end region 20B of the tread 20 is a spiral tread so that the tread end during vulcanization molding It is possible to suppress wrinkles and the like in the tread and to make the tread thickness uniform. In this way, when the tire case has a large circumferential length difference, if the end region 20B is a spiral tread, the effect of uniforming the tread thickness becomes more remarkable.

Further, by using the belt layer 18 as a spiral belt, the carcass ply 16 is reinforced more strongly, and higher high-speed durability can be obtained.
[Second Embodiment]
3, in the pneumatic tire 200 for a motorcycle according to the present embodiment, the end region 20B of the tread 20 is configured in, for example, two layers, and for example, any layer is a spiral tread.

  However, in the tread side outermost layer 24, the belt-like rubber 22 is spirally wound from the outer side in the tire axial direction to the inner side as in the first embodiment, but in the lower layer 30 on the tire center side, On the contrary, the belt-like rubber 22 is spirally wound from the inner side toward the outer side in the tire axial direction, and the inclination direction of the belt-like rubber 22 is reversed between the tread side outermost layer 24 and the lower layer 30.

Since other parts are the same as those of the first embodiment of the present invention, the same parts are denoted by the same reference numerals and description thereof will be omitted.
(Function)
As shown in FIG. 4, in the tread side outermost layer 24 in the end region 20B, the belt-like rubber 22 is spirally wound from the outer side in the tire axial direction toward the inner side, so that camber travel frequently used in two-wheeled vehicles is performed. Sometimes, even if stress is applied to the end region 20B in the direction of the arrow F due to friction with the road surface 28, the end of the portion that was the belt-like rubber 22 before vulcanization does not face the direction of the stress. Therefore, it is difficult for wrinkle-like uneven wear to occur at the end, and the uneven wear performance is high.

  Further, since the boundary surface 20C is inclined in the tire radial cross section so that the distance to the boundary surface 20C between the central region 20A and the end region 20B gradually increases outward in the tire radial direction, As shown in FIG. 4, when camber travels, for example, when stress is applied from the center region 20A to the end region 20B of the tread due to friction with the road surface 28, it is difficult to cause scissors and open splices on the boundary surface 20C. High nature.

  In addition, in the lower layer 30 of the end region 20B, the belt-like rubber 22 is wound in the opposite direction to the tread side outermost layer 24 and vulcanized, and the portion that was the belt-like rubber 22 before this vulcanization is removed from the road surface 28. Therefore, the tread rigidity is high and cornering at higher speed is possible.

In the illustrated embodiment, the overlapped belt-like rubber 22 is drawn so that there is a clear boundary. However, this is for the purpose of explanation, and when the same kind of unvulcanized rubber is vulcanized and molded side by side, The boundaries do not always remain clear. The same applies to the boundary surface 20C.
(Test example)
Under the conditions shown in Table 1, tires according to the example (FIG. 1), the comparative example (FIG. 5), and the conventional example (not shown) are manufactured as prototypes, and the difference in rubber thickness on the tire circumference at the tread edge is measured. Tests were conducted on run-out, uniformity (indoor measurement), vibration and wear conditions (actual vehicle evaluation). The tire sizes are both 190 / 55R17.

  5, 300 is a pneumatic tire for a motorcycle according to a comparative example, 302 is a bead portion, 304 is a bead core, 306 is a carcass ply, 308 is a belt layer, 310 is a tread, 310A is a central region, and 310B is an end region. , 310C is a boundary surface, and 312 is a belt-like rubber.

  The rubber thickness difference on the tire circumference was measured by the thickness A in FIG. 1, and the runout on the circumference was measured in B in FIG. The same applies to the comparative example and the conventional example.

  In the test results shown in Table 2, the rubber thickness difference on the tire circumference and the runout on the circumference are indicated by an index based on Example 100, and the larger the value, the better the result.

  In addition, fluctuations in indoor measurements are compared with measurement data of uniformity, and are evaluated on a 10-point scale.

  The vibration in the actual vehicle evaluation is a feeling evaluation by the occupant, and the wear state is an evaluation by a tread observation evaluation method after traveling a predetermined distance. All values are out of 10 points.

  According to this test example, the rubber thickness difference on the tire circumference and the runout on the circumference of the example and the comparative example are reduced by half compared to the conventional example, and also about uniformity and vibration. Also, it is improved over the conventional example.

  Regarding the vibration, the evaluation of the comparative example is the best, but in the comparative example, the winding direction of the belt-like rubber is opposite to that of the example, so that the wear state remains at the same level as the conventional example.

  In the embodiment, since the winding direction of the belt-like rubber is appropriate, both vibration and wear state are improved.

1 is a cross-sectional view of a pneumatic tire for a motorcycle according to a first embodiment. 1 is a cross-sectional view showing a ground contact state with a road surface when traveling with a camber using a pneumatic tire for a motorcycle according to a first embodiment. It is sectional drawing of the pneumatic tire for motorcycles concerning 2nd Embodiment. It is sectional drawing which shows a grounding state with the road surface when carrying out camber driving | running | working using the pneumatic tire for motorcycles concerning 2nd Embodiment. It is sectional drawing of the pneumatic tire for motorcycles concerning a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Bead part 14 Bead core 16 Carcass ply 18 Belt layer 20 Tread 20A Center area 20B End area 20C Boundary surface 22 Band-shaped rubber 24 Tread side outermost layer 26 Band-shaped rubber 100 Pneumatic tire for motorcycle 200 Pneumatic tire for motorcycle

Claims (8)

An unvulcanized tread rubber member is provided on the outer peripheral surface of a band assembly including at least a pair of bead cores, a carcass ply straddling one bead core and the other bead core, and a belt layer provided on the outer peripheral surface of the carcass ply. A method for producing a pneumatic tire for a motorcycle, comprising forming a raw tire by pasting and vulcanizing the raw tire using a vulcanization mold,
The tread is divided into a central region and an end region, and as the tread rubber member of at least the tread surface side outermost layer of the end region, unvulcanized belt-like rubber is spirally wound in the tire circumferential direction and the tire axial direction As the tread rubber member of the outermost layer at least on the tread surface in the central region, the unvulcanized band-shaped rubber having a width wider than that of the unvulcanized belt-shaped rubber is provided in the tire circumferential direction. A method for producing a pneumatic tire for a motorcycle, wherein the tire is wound once.   Affixing the tread rubber member so that a distance from a tire equatorial plane in the tire axial direction of the tread to a boundary surface between the center region and the end region gradually increases outward in the tire radial direction; The method for manufacturing a pneumatic tire for a motorcycle according to claim 1, wherein the pneumatic tire is a motorcycle.   The method for manufacturing a pneumatic tire for a motorcycle according to claim 1 or 2, wherein a strip formed by rubber-covering at least one cord as the belt layer is spirally wound in a tire circumferential direction. . The center region is constructed by assembling a finished tire on a regular rim, filling a regular internal pressure, and in a no-load state, the distance in the tire axial direction from the tire equator is x, and the tire equator from the tread tread at the position of the distance x. When the distance in the tire radial direction to the tread surface on the surface is y, the drop rate (y / x × 100) is a region having a maximum of 10 to 35%,
The motorcycle according to any one of claims 1 to 3, wherein the end region is a region that is on an outer side in the tire axial direction with respect to the central region on both sides of the tire equator plane. A method of manufacturing a pneumatic tire. At least one layer of carcass ply wound around the bead core disposed in the toroid between the pair of bead portions and wound back from the inside to the outside, and at least one belt layer positioned radially outward of the carcass ply And a pneumatic tire for a motorcycle having a tread located radially outward of the belt layer,
When the tread is divided into a central region and an end region,
At least the tread surface side outermost layer in the end region is a spiral tread in which an unvulcanized belt-like rubber is spirally wound in the tire circumferential direction and is lap-wrapped from the outer side to the inner side in the tire axial direction and vulcanized. And
At least the outermost layer on the tread surface side of the central region is a band-wound tread formed by vulcanizing and molding an unvulcanized band-shaped rubber having a width wider than that of the belt-shaped rubber in the tire circumferential direction. Pneumatic tire for motorcycles.   The boundary surface is inclined in the tire radial cross section so that the distance from the tire equatorial plane in the tire axial direction to the boundary surface between the central region and the end region gradually increases outward in the tire radial direction. The pneumatic tire for a motorcycle according to claim 5, wherein the pneumatic tire is a motorcycle.   The motorcycle according to claim 5 or 6, wherein the belt layer is a spiral belt in which a strip formed by covering at least one cord with a rubber is spirally wound in a tire circumferential direction. Pneumatic tires. The central region is assembled to a normal rim, filled with normal internal pressure, and in a no-load state, the distance in the tire axial direction from the tire equator surface is x, and the tread tread surface at the position of the distance x to the tire equatorial surface When the distance in the tire radial direction to the tread surface is y, the drop rate (y / x × 100) is a region having a maximum of 10 to 35%,
The motorcycle according to any one of claims 5 to 7, wherein the end region is a region which is on the outer side in the tire axial direction with respect to the center region on both sides of the tire equator plane. Pneumatic tire.

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