Recently, a radial ply carcass has been used for motorcycle tires. Such a motorcycle radial tire has been made based on technique for four-wheeled vehicle tires, e.g. passenger car tires. That is, the tire has been provided with a belt reinforcement formed as follows: a rubberized fabric (d) is cut bias at a small angle (alpha) to the cord direction as shown in FIG. 6, which is usually 15 to 30 degrees; and the cut fabric (e) is wound around a carcass with connecting the ends (f) as shown in FIG. 5 to form an annular belt reinforcement (a), and accordingly, the laid angle of the belt cords (b) to the tire equator becomes the same bias angle (alpha). In such a bias belt structure, however, steering stability during straight running and cornering, especially at high speed, is not good.
On the other hand, Japanese Utility-Model Publication No. 58-160805 discloses a belt making method, in which a belt cord is wound spirally at a generally zero angle to the circumferential direction of the tire to form a jointless belt. When this is used in the motorcycle tire instead of the conventional belt, stability during high speed straight running is improved, but road grip during cornering is deteriorated.
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