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Nakagawa, Hidemitsu; Sumida, Takashi; |
Pneumatic motorcycle tire

A pneumatic tire for a two-wheeled vehicle having high lateral stiffness and exhibiting improved steering stability has a tread pattern defined in a tread portion by numerous sets of combination lug groove patterns. In this tread portion, one set of the left and right sides of the lug groove patterns is reverse W-shaped as a whole in the tire rolling direction, each of mid bending points P on both sides of the reverse W-shape is arranged at the region of 20-80% of a tire tread half width TW from a tire central circumferential line EC, an angle of the lug groove component to a tire shoulder portion from the mid bending point P is 20-70.degree. with respect to a tire equatorial plane E, and an angle of the lug groove component to the tire central circumferential line EC from the bending point P is 20-70.degree. with respect to the tire equatorial plane E.


What is claimed is:
1. A pneumatic motorcycle tire comprising; a zigzag circumferential groove, numerous sets of lug groove patterns, each set of lug groove patterns including a left lug groove pattern on one side of said zig zag circumferential groove and a right lug groove pattern on the other side of zig zag circumferential groove, one set of the left and right lug groove patterns being a reverse W-shape as a whole in a tire rolling directs, each of the left and right lug groove patterns of the reverse W-shape having a mid bending point which is arranged in a region of 35-65% of a tire half width TW from a tire central circumferential line, a first lug groove component extending from the mid bending point to a tire shoulder portion, a second lug groove component extending from the mid bending point to the tire central circumferential line, and a third lug groove component extending from said second lug groove component to the tire shoulder portion, an angle .alpha. of the first lug groove component extending from the mid bending point to the tire shoulder portion being 20-70.degree. with respect to the tire equatorial plane and an angle .beta. of the second lug groove component extending from the mid bending point to the tire central circumferential line being 20-70.degree. with respect to the tire equatorial plane wherein, the left lug groove pattern and the right lug groove pattern of the one set are offset in the circumferential direction.
2. A pneumatic motorcycle tire according to claim 1, wherein said angle .alpha. is 40-60.degree. and said angle .beta. is 25-45.degree., and the angle .alpha. is greater than the angle .beta..
3. A pneumatic motorycle tire according to claim 1, wherein said zig-zag circumferential groove is arranged in a region from the tire central circumferential line to 35% of the tire tread half width.
4. A pneumatic motorcycle tire according to claim 1, wherein a pitch of said lug groove patterns is 1/100-1/20 of the circumferential length of said tire.
5. A pneumatic motorcycle tire according to claim 1, wherein the left lug groove pattern and the right lug groove pattern are offset in the circumferential direction by an offset amount, wherein said offset amount is more than 0 times the circumferential length of the tire and less than 1/20 of the circumferential length of the tire.
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