JP6043065B2 - Method for manufacturing motorcycle tire - Google Patents

Description

  The present invention relates to a motorcycle tire that can improve grip performance and abrasion resistance performance or stability in a well-balanced manner.

  Conventionally, in order to increase tire uniformity, a long belt-like ply in which a cord array in which one band cord or a plurality of band cords are arranged in parallel is covered with a topping rubber on the outer side in the radial direction of the carcass. 2. Description of the Related Art A motorcycle tire having a band layer made of a jointless ply spirally wound in the tire circumferential direction is known.

  However, it has been desired to further improve grip performance, ablation performance, or stability in such motorcycle tires, particularly racing motorcycle tires intended for circuit running. As a related technique, there is Patent Document 1 below.

JP-A-9-118109

The present invention has been devised in view of the actual situation as described above, and an organic fiber cord of at least two reinforcing plies for forming a tread reinforcing layer by adding a band layer to the outside of the carcass and forming the tread reinforcing layer. The present invention provides a method for manufacturing a tire for a motorcycle that can improve the grip performance and abrasion resistance or stability in a well-balanced manner based on the difference in the angle with respect to the tire circumferential direction between the center region and the shoulder region. The main purpose.

The present invention relates to a carcass extending from a tread portion through a sidewall portion to a bead core of a bead portion, a band layer disposed outside the carcass in the tire radial direction and inside the tread portion, and at least the carcass tire radial direction outside. tread reinforcing layer and the ingredients to give a that is disposed, the band layer, the tire circumferential a single band cord or elongated strip ply coated plural band cords arranged in parallel to the coding sequence of a by the topping rubber The tread reinforcing layer is composed of at least two reinforcing plies covered with a topping rubber and overlapped inside and outside in the tire radial direction, the jointless ply spirally wound in the direction, The reinforcement ply is the distance along the tread surface between the tread edge and the tire equator from the tire equator. In the center region that is 1/3 of the half width of the tread, the angle θc with respect to the tire circumferential direction of the organic fiber cord is 65 to 85 °, in the shoulder region that is 1/3 of the tread half width from the tread end, A method for manufacturing a motorcycle tire for manufacturing a motorcycle tire having an angle θs of 66 to 86 ° with respect to a tire circumferential direction of the organic fiber cord and 1 to 8 ° larger than the angle θc of the center region , The reinforcing ply forming step of forming the reinforcing ply includes a sheet-like ply in which a plurality of organic fiber cords are arranged in parallel, between a pair of rotatable rotating parts provided on both sides in the tire axial direction and the rotating parts. And a winding step for winding the former over the pair of rotating parts, and rotation for rotating the pair of rotating parts in a reverse direction. Characterized in that it comprises a degree.

In the method for manufacturing a motorcycle tire according to the present invention, the reinforcing ply has the angle θc of the center region of 65 to 75 °, and the angle θs of the shoulder region is greater than the angle θc of the center region. Is preferably 2 to 5 ° larger .

The present invention relates to a carcass extending from a tread portion through a sidewall portion to a bead core of a bead portion, a band layer disposed outside the carcass in the tire radial direction and inside the tread portion, and at least the carcass tire radial direction outside. tread reinforcing layer and the ingredients to give a that is disposed, the band layer, the tire circumferential a single band cord or elongated strip ply coated plural band cords arranged in parallel to the coding sequence of a by the topping rubber The tread reinforcing layer is composed of at least two reinforcing plies covered with a topping rubber and overlapped inside and outside in the tire radial direction, the jointless ply spirally wound in the direction, The reinforcement ply is the distance along the tread surface between the tread edge and the tire equator from the tire equator. In the center region that is 1/3 of the half width of the tread, the angle θc with respect to the tire circumferential direction of the organic fiber cord is 65 to 85 °, in the shoulder region that is 1/3 of the tread half width from the tread end, A method for manufacturing a motorcycle tire for manufacturing a motorcycle tire having an angle θs with respect to a tire circumferential direction of the organic fiber cord of 64 to 84 ° and 1 to 8 ° smaller than the angle θc of the center region , The reinforcing ply forming step of forming the reinforcing ply includes a sheet-like ply in which a plurality of organic fiber cords are arranged in parallel, between a pair of rotatable rotating parts provided on both sides in the tire axial direction and the rotating parts. And a winding step for winding the former over the pair of rotating parts, and rotation for rotating the pair of rotating parts in a reverse direction. Characterized in that it comprises a degree.

In the method for manufacturing a tire for a motorcycle according to the present invention, the reinforcing ply has the angle θc of the center region of 70 to 80 °, and the angle θs of the shoulder region is the angle θc of the center region. It is desirable that the angle is 2 to 5 ° smaller than that .

In the method for manufacturing a motorcycle tire according to the present invention, the tread reinforcing layer includes three reinforcing plies, and the outer end in the tire axial direction of the innermost ply arranged on the innermost side in the tire radial direction is An intermediate ply tire shaft disposed at a distance of −10 to 40 mm on the tire equator side along the tread surface from the outer end of the band layer in the tire axial direction, and disposed on the outer side in the tire radial direction of the innermost ply. The outer end in the direction is disposed at a distance of 20 to 50 mm on the tire equator side along the tread surface from the outer end in the tire axial direction of the innermost ply, and is disposed on the outer side in the tire radial direction of the intermediate ply. The outer end of the outermost ply in the tire axial direction is preferably disposed at a distance of 40 to 70 mm along the tread surface from the outer end of the intermediate ply in the tire axial direction toward the tire equator .

In the method for manufacturing a tire for a motorcycle according to the present invention, it is desirable that an intermediate elongation of the organic fiber cord of the tread reinforcing layer is 1.0 to 2.0% .

In the method for manufacturing a tire for a motorcycle according to the present invention, the tread reinforcing layer includes an end (lines / 5 cm) of cords driven per 5 cm ply width of the reinforcing ply, and a thickness (dtex) of the organic fiber cord. And the product of the number of twists (the number) of the cords is preferably 18,000 to 34,000 .

  In the motorcycle tire according to the first aspect of the present invention, a carcass extending from the tread portion to the bead core of the bead portion through the sidewall portion, and a band disposed outside the carcass in the tire radial direction and inside the tread portion. Motorcycle tire comprising a layer and a tread reinforcing layer arranged at least on the outer side in the tire radial direction of the carcass, wherein the band layer has one band cord or a plurality of band cords arranged in parallel It consists of a jointless ply in which a long belt-like ply, in which the cord array body is covered with a topping rubber, is spirally wound in the tire circumferential direction. Such a motorcycle tire has a belt layer made of a seamless jointless ply, so that the uniformity is improved.

  The tread reinforcing layer is composed of at least two reinforcing plies in which a plurality of organic fiber cords are covered with a topping rubber and overlapped inside and outside in the tire radial direction. Thus, since the tread reinforcing layer is composed of at least two reinforcing plies, the rigidity of the tread portion is increased and the steering stability performance is improved.

  The reinforcing ply has a tire circumferential direction of the organic fiber cord in a center region which is a region of 1/3 of a tread half width which is a distance along the tread surface between the tread end and the tire equator from the tire equator. The angle θc with respect to the tire circumferential direction of the organic fiber cord is 66 to 86 ° and the angle of the center region in the shoulder region that is an angle θc of 65 to 85 ° with respect to the tire tread half width from the tread end 1 to 8 ° larger. As a result, the density of the organic fiber cords arranged in the shoulder region is lower than that in the center region, and the rigidity of the shoulder region is relaxed compared to the center region. Therefore, since the ground contact pressure in the shoulder region is reduced, the grip performance and anti-abrasion performance during turning are improved in a well-balanced manner.

  In the motorcycle tire according to claim 3, the angle θc of the center region of the tread reinforcing layer is 65 to 85 °, the angle θs of the shoulder region is 64 to 84 °, and the angle of the center region. Also make it 1-8 degrees smaller. Thereby, the density of the organic fiber cord arranged in the center region is less than that in the shoulder region, and the rigidity of the center region is reduced as compared with the shoulder region. Accordingly, the contact pressure in the center region is reduced, and the grip performance and stability during straight traveling are improved.

1 is a cross-sectional view in a normal state showing one embodiment of a motorcycle tire of the present invention. (A) is a development view of the tread reinforcing layer in FIG. 1, and (b) is a development view of the innermost ply in (a). (A) is a development view of a tread reinforcing layer according to another embodiment of the present invention, and (b) is a development view of the innermost ply of (a). (A) is a perspective view of the former which forms a reinforcement ply, (b) is a side view which shows the formation method of the reinforcement ply using the former of (a).

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a tire meridian cross-sectional view including a tire rotation axis in a normal state of a motorcycle tire (hereinafter, simply referred to as “tire”) 1 of the present embodiment. In this specification, the “normal state” means that the tire is assembled to a normal rim (not shown) and filled with a normal internal pressure and is in an unloaded state, and unless otherwise specified, the dimensions of each part of the tire. Etc. are values measured in this normal state.

  The “regular rim” is a rim defined by each standard for each tire in a standard system including the standard on which the tire is based. “JATMA” is a “standard rim”, and TRA is “Design”. "Rim" or "Measuring Rim" for ETRTO. In addition, the “regular internal pressure” is an air pressure determined by each standard for each tire in the standard system including the standard on which the tire is based. TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES "Maximum value", ETRTO, "INFLATION PRESSURE".

  The tire 1 of the present embodiment includes a carcass 6 that extends from the tread portion 2 through the sidewall portion 3 to the bead core 5 of the bead portion 4, and a band layer that is disposed outside the carcass 6 in the tire radial direction and inside the tread portion 2. 7 and a tread reinforcing layer 8 disposed between the carcass 6 and the band layer 7.

  The tread portion 2 is curved in an arc shape so as to protrude outward in the tire radial direction, and the tread ends Te and Te which are the outermost positions in the tire axial direction are the outermost in the tire axial direction. Provided. In this specification, the distance along the tread surface 2a between the tread ends Te and Te is the tread width TW, and the distance along the tread surface 2a between the tread end Te and the tire equator C is the tread half width BW. .

  The carcass 6 includes at least one carcass ply in which carcass cords are arranged at an angle of 60 to 90 ° with respect to the tire equator C. The carcass 6 of the present embodiment is composed of, for example, one carcass ply 6A inclined at 90 ° with respect to the tire equator C. As the carcass cord, an organic fiber cord such as nylon, polyester, or rayon is preferably employed in order to ensure the rigidity of the tread portion 2 and improve the riding comfort.

  The carcass ply 6A includes a main body portion 6a extending from the tread portion 2 through the sidewall portion 3 to the bead core 5 of the bead portion 4, and a turning portion 6b turned around the bead core 5 from the inner side to the outer side in the tire axial direction. It is comprised as what is called a winding ply containing. A bead apex Ba made of hard rubber that extends in a radially outward direction from the bead core 5 is disposed between the main body portion 6a and the folded portion 6b. Thereby, the bead part 4 and the sidewall part 3 are reinforced. The carcass 6 may be composed of a plurality of carcass plies.

  The band layer 7 is disposed on the outer side in the tire radial direction of the carcass 6 and inside the tread portion 2. In the present embodiment, the band layer 7 is disposed on the outer side in the tire radial direction of the tread reinforcing layer 8. The width Wb, which is the length along the tread surface 2a between the outer ends 7e, 7e in the tire axial direction of the band layer 7, is preferably 105 to 80% of the tread width TW. The band layer 7 may be disposed on the inner side of the tread reinforcing layer 8 in the tire radial direction.

  The band layer 7 of this embodiment is formed of a jointless ply formed by winding a rubber-coated band cord in a spiral shape at an angle of 10 degrees or less with respect to the tire circumferential direction.

  The jointless ply is formed of a long belt-like ply 7A in which a cord array in which a plurality of (for example, 3 to 10) band cords are arranged in parallel is covered with a topping rubber. The belt-like ply 7A may be a single band cord covered with a topping rubber. As the band cord of the band layer 7, for example, an organic fiber cord such as aramid, nylon, polyester, or rayon is suitably employed, and an aramid cord is employed in the present embodiment.

  The tread reinforcing layer 8 is composed of at least two reinforcing plies 9 that overlap inside and outside in the tire radial direction, and in this embodiment, three reinforcing plies 9.

  The reinforcing ply 9 includes an innermost ply 9A arranged on the innermost side in the tire radial direction, an intermediate ply 9B arranged on the outer side in the tire radial direction of the innermost ply 9A, and a tire radial direction of the intermediate ply 9B. It is composed of three plies of the outermost ply 9C arranged on the outside.

  The outer end 9Ae in the tire axial direction of the innermost ply 9A is disposed at a distance of −10 to 40 mm from the outer end 7e in the tire axial direction of the band layer 7 along the tread surface 2a to the tire equator C side. Is desirable. Further, the outer end 9Be in the tire axial direction of the intermediate ply 9B is preferably arranged at a distance of 20 to 50 mm from the outer end 9Ae of the innermost ply 9A along the tread surface 2a to the tire equator side. The outer end 9Ce of the outermost ply 9C in the tire axial direction is preferably arranged at a distance of 40 to 70 mm from the outer end 9Be of the intermediate ply 9B along the tread surface 2a to the tire equator C side. That is, the reinforcement ply 9 has the maximum width in the tire axial direction of the innermost ply 9A disposed on the innermost side in the tire radial direction, and the width in the tire axial direction of the outermost ply 9C disposed on the outermost side in the tire radial direction. Is formed to a minimum. In addition, the minus display of the above-described distance indicates that the outer end 9Ae of the innermost ply 9A may be arranged from the outer end 7e of the band layer 7 to the tread end Te side.

  The reinforcing ply 9 as described above has a thicker reinforcing ply layer disposed on the tire equator C side and a thinner reinforcing ply layer disposed on the shoulder side, so that the rigidity on the tire equator C side is increased. As a result, the straight running stability is improved and the rigidity on the shoulder side is eased, so that the ground pressure during turning is reduced and the gripping force during turning is secured. From this point of view, the width W1 along the tread surface 2a of the outermost ply 9C is the largest among the reinforcement plies 9, and the width W2 along the tread surface 2a of the innermost ply 9A is equal to the reinforcement ply 9. Among them, it may be formed the smallest.

  Such a reinforcing ply 9 is formed of, for example, a sheet-like ply in which a plurality of organic fiber cords 11 covered with a topping rubber are arranged in parallel, and both end portions in the tire circumferential direction are overlapped. To form a ring. As the organic fiber cord 11 of the reinforcing ply 9, for example, aramid, nylon, polyester, or rayon is suitably employed.

As shown in FIG. 2 (a), the reinforcing ply 9 according to the present embodiment has the organic fiber cord 11 in the tire circumferential direction in the center region Ce, which is one third of the tread half width BW from the tire equator C. The angle θc is formed at 65 to 85 °. Further, in the shoulder region Sh that is a region of １ ／ of the tread half width BW from the tread end Te, the angle θs with respect to the tire circumferential direction of the organic fiber cord 11 is 66 to 86 ° and is 1 than the angle θc of the center region Ce. -8 ° larger. As shown in FIG. 2B, the reinforcing ply 9 has a lower density of the organic fiber cord 11 disposed in the shoulder region Sh than the center region Ce, so that the shoulder is smaller than the center region Ce. The rigidity of the region Sh is reduced. Therefore, since the contact pressure in the shoulder region Sh is reduced, the grip performance, anti-abrasion performance, and slide control performance during turning are improved in a well-balanced manner.

  In order to effectively exhibit the above-described action, the reinforcement ply 9 has the angle θc of the center region Ce of 65 to 75 ° and the angle θs of the shoulder region Sh of 2 to 5 ° larger than the angle θc. It is desirable to be formed.

  In the present embodiment, the organic fiber cords 11 of all the plies of the innermost ply 9A, the intermediate ply 9B, and the outermost ply 9C are defined at the above-described angle in order to exhibit the above-described action more effectively. In the present embodiment, the intermediate ply 9B, the innermost ply 9A, and the outermost ply 9C have different inclination directions with respect to the tire circumferential direction.

  Further, the reinforcing ply 9 has an end (lines / 5 cm) which is the number of driven organic fiber cords 11 per 5 cm in width, a thickness (dtex) of the organic fiber cords 11 and a twist number (books) of the organic fiber cords 11. It is desirable that the product is 18000 to 34000 in the crown region Ce. When the product is less than 18000, the rigidity of the tread portion 2 becomes excessively small, and the grip performance and anti-abrasion performance during straight running may be deteriorated. On the other hand, if the product exceeds 34,000, the topping rubber does not sufficiently penetrate between the cords and the durability may be deteriorated, and the rigidity of the tread portion 2 is excessively increased, and thus the stability is deteriorated. There is a risk. The number of twists (the number) of the organic fiber cord is 2 which is the number after “/” when the organic fiber cord is indicated as 440 dtex / 2 or 800 dtex / 2.

  From this point of view, when the end, which is the number of cords driven per 5 cm of ply width, is a two-strand with an organic fiber cord thickness of 440 dtex, 21 to 31 in the center region Ce and 25 in the shoulder region Sh. When the thickness of the organic fiber cord is two twists of 800 dtex, it is preferably 12 to 21 in the center region Ce and 15 to 27 in the shoulder region Sh.

  In the present embodiment, the intermediate elongation of the organic fiber cord 11 of the tread reinforcing layer 8 is desirably 1.0 to 2.0%. Thereby, the rigidity of the tread portion 2 and the ground pressure are improved in a well-balanced manner. The “intermediate elongation” is “elongation at constant load” measured according to “Standard Time Test” in Section 8.7 of JISL1017, and is the value of the cord after dip processing taken from the tire. Indicated by In the present embodiment, the constant load is set to 32N.

As another embodiment of the present invention, as shown in FIG. 3A, the reinforcing ply 9 is formed such that the angle θc of the center region Ce is 65 to 85 °, and the shoulder region Sh The angle θs is 64 to 84 ° and 1 to 8 ° smaller than the angle θc of the center region Ce. Unlike the embodiment of FIG. 2, the reinforcing ply 9 has a density of organic fiber cords arranged in the shoulder region Sh rather than the center region Ce as shown in FIG. 3 (b). The rigidity of the region Sh is increased and the rigidity of the center region Ce is relaxed. Accordingly, the contact pressure in the center region Ce is reduced, and the grip performance, stability, and motion performance during straight traveling are improved.

  In order to exhibit the above-mentioned action more effectively, the reinforcing ply 9 has the angle θc of the center region Ce of 70 to 80 ° and the angle θs of the shoulder region Sh of 2 to 5 ° than the angle θc. It is desirable to form it small.

  FIG. 4A shows a former f for forming such a reinforcing ply 9. The former f has a rotatable rotating part f1 provided on both sides in the tire axial direction, and a fixed part f2 arranged between the rotating parts f1 and f1.

  And in order to manufacture the reinforcement ply 9, as shown in FIG.4 (b), the sheet-like reinforcement ply 9 is wound around the former f over a pair of rotation parts f1 and f1, and the tire circumferential direction Both ends of the two are overlapped and the rotating parts f1 on both sides rotate in opposite directions. Thereby, the reinforcement ply 9 of this embodiment is formed.

  As mentioned above, although the pneumatic tire of this invention was demonstrated in detail, it cannot be overemphasized that this invention can be changed into various aspects, without being limited to said specific embodiment.

The slick tires for motorcycles of size 210 / 60R420 (rear) and 125 / 80R420 (front) having the basic configuration shown in FIG. 1 are manufactured based on the specifications in Table 1, and each sample tire is a motorcycle (exhaust). A variety of tests were carried out. The common specifications are as follows.
(rear)
Tread width TW: 205mm
Rim width: 6.25 inches Internal pressure: 130 kPa
Carcass cord material: Rayon Carcass cord angle with respect to tire circumferential direction: 88 degrees Band cord material: Aramid Band cord angle with respect to tire circumferential direction: 0 degrees (front)
Tread width TW: 120mm
Rim width: 3.50 inches Internal pressure: 200 kPa
Carcass cord material: Nylon Carcass cord angle with respect to tire circumferential direction: 82 degrees Band cord material: Aramid Band cord angle with respect to tire circumferential direction: 28 degrees <Matters common to rear and front>
(Tread reinforcement layer)
Organic fiber cord material: Aramid Distance between outer end of innermost ply and outer end of band layer: 20mm
Distance between the outer end of the middle ply and the outer end of the innermost ply: 40 mm
Distance between outer end of outermost ply and outer end of intermediate ply: 20mm
Width along tread surface: innermost ply> band layer> middle ply> outermost ply (band layer)
Band layer width (Wb / TW): 86%
The test method is as follows.

<Side grip, traction grip, stability performance, exercise performance, slide control performance>
“Side grip,” “traction grip,” “stable performance,” “movement performance,” and “slide control performance” of the above motorcycles on the dry asphalt road test course were evaluated based on the driver's sensuality. The result is displayed by a 10-point method in which Comparative Example 1 is 5 points and the highest point is 10 points.

<Ablation resistance>
After each test, using a drum tester, the rear tire was visually inspected after running on the drum at a speed of 120 km / h for 30 minutes under a load (1.75 kN) condition. It was confirmed by. The result is displayed by a 10-point method in which Comparative Example 1 is 5 points and the highest point is 10 points.

  As a result of the test, it can be confirmed that the tires of the examples have significantly improved various performances such as grip performance, abrasion resistance performance, and stability, as compared with the tires of the comparative examples.

2a tread surface 6 carcass 7 band layer 8 tread reinforcement layer 9 reinforcement ply 11 organic fiber cord BW tread half width C tire equator Ce center area Sh shoulder area Te tread edge

Claims (7)

A carcass extending from the tread portion to the bead core of the bead portion through the sidewall portion, a band layer disposed outside the carcass in the tire radial direction and inside the tread portion, and disposed at least outside the carcass in the tire radial direction. With tread reinforcement layer,
The band layer includes a jointless ply in which a long band ply covered with a topping rubber is coated with a cord array in which one band cord or a plurality of band cords are arranged in parallel is spirally wound in the tire circumferential direction. Become
The tread reinforcing layer is composed of at least two reinforcing plies in which a plurality of organic fiber cords are covered with a topping rubber and overlapped inside and outside in the tire radial direction,
The reinforcing ply is an angle of the organic fiber cord with respect to the tire circumferential direction in a center region which is a region of 1/3 of a half width of the tread which is a distance along the tread surface between the tread end and the tire equator from the tire equator. θc is 65 to 85 °, and an angle θs with respect to the tire circumferential direction of the organic fiber cord is 66 to 86 ° and the angle θc of the center region in the shoulder region that is 1/3 of the tread half width from the tread end. Is a manufacturing method of a motorcycle tire for manufacturing a motorcycle tire larger by 1 to 8 degrees,
The reinforcing ply forming step of forming the reinforcing ply includes a sheet-like ply in which a plurality of organic fiber cords are arranged in parallel, a pair of rotatable rotating parts provided on both sides in the tire axial direction, and the rotating part A tire for a motorcycle, comprising: a winding step of winding over the pair of rotating portions of the former having a fixed portion disposed therebetween; and a rotating step of rotating the pair of rotating portions in opposite directions. Manufacturing method.   The motorcycle according to claim 1, wherein the reinforcing ply has an angle θc of 65 to 75 ° in the center region, and the angle θs of the shoulder region is 2 to 5 ° larger than the angle θc of the center region. Tire manufacturing method. A carcass extending from the tread portion to the bead core of the bead portion through the sidewall portion, a band layer disposed outside the carcass in the tire radial direction and inside the tread portion, and disposed at least outside the carcass in the tire radial direction. With tread reinforcement layer,
The band layer includes a jointless ply in which a long band ply covered with a topping rubber is coated with a cord array in which one band cord or a plurality of band cords are arranged in parallel is spirally wound in the tire circumferential direction. Become
The tread reinforcing layer is composed of at least two reinforcing plies in which a plurality of organic fiber cords are covered with a topping rubber and overlapped inside and outside in the tire radial direction,
The reinforcing ply is an angle of the organic fiber cord with respect to the tire circumferential direction in a center region which is a region of 1/3 of a half width of the tread which is a distance along the tread surface between the tread end and the tire equator from the tire equator. θc is 65 to 85 °, and an angle θs with respect to the tire circumferential direction of the organic fiber cord is 64 to 84 ° and the angle θc of the center region in the shoulder region that is 1/3 of the tread half width from the tread end. Is a manufacturing method of a motorcycle tire for manufacturing a motorcycle tire 1 to 8 degrees smaller,
The reinforcing ply forming step of forming the reinforcing ply includes a sheet-like ply in which a plurality of organic fiber cords are arranged in parallel, a pair of rotatable rotating parts provided on both sides in the tire axial direction, and the rotating part A tire for a motorcycle, comprising: a winding step of winding over the pair of rotating portions of the former having a fixed portion disposed therebetween; and a rotating step of rotating the pair of rotating portions in opposite directions. Manufacturing method.   The automatic reinforcement according to claim 3, wherein the angle θc of the center region is 70 to 80 °, and the angle θs of the shoulder region is 2 to 5 ° smaller than the angle θc of the center region. A method for manufacturing a tire for a motorcycle.   The tread reinforcing layer includes three reinforcing plies, and the outer end in the tire axial direction of the innermost ply disposed on the innermost side in the tire radial direction extends from the outer end in the tire axial direction of the band layer to the tread surface. Along the tire equator side at a distance of −10 to 40 mm, and the outer end in the tire axial direction of the intermediate ply arranged on the outer side in the tire radial direction of the innermost ply is the tire axis of the innermost ply. The outer end in the tire axial direction of the outermost ply that is arranged on the tire equator side along the tread surface from the outer end in the direction at a distance of 20 to 50 mm, and is arranged on the outer side in the tire radial direction of the intermediate ply, The method for manufacturing a motorcycle tire according to any one of claims 1 to 4, wherein the tire is disposed at a distance of 40 to 70 mm from the outer end in the tire axial direction of the intermediate ply along the tread surface to the tire equator side. The method for manufacturing a tire for a motorcycle according to any one of claims 1 to 5, wherein the organic fiber cord of the tread reinforcing layer has an intermediate elongation of 1.0 to 2.0% with a constant load of 32N. .   The tread reinforcing layer has a product of 18000 which is the number of cords driven per 5 cm ply width of the reinforcing ply (lines / 5 cm), the thickness of the organic fiber cord (dtex), and the number of twists of the cord (1). The method for manufacturing a tire for a motorcycle according to any one of claims 1 to 6.

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