| 摘要 |
PROBLEM TO BE SOLVED: To enable a smooth gear change by reducing a friction area between a shift arm and a lock pinion while suppressing the lowering of the rigidity of the shift arm, in a power unit for a saddle-riding type vehicle in which a change mechanism for turning the shift drum comprises a shift spindle and the shift arm fixed to the spindle by being engaged with the lock pin at the shift drum side.SOLUTION: At a shift arm 62, there are formed a long-hole shaped engagement hole 83 which is penetrated with and engaged with a lock pin 61, and extends along one diameter line of a shit spindle 45, and a circular penetration hole 84 which is penetrated with an interlocking shaft 82 coaxially connected to a shift drum so as to be relatively non-rotatable, and sets a center axial line of the shift spindle 45 as a center. A portion penetrating at least the penetration hole 84 of the interlocking shaft 82 is formed smaller than the lock pin 61 in diameter, and a width d1 of the penetration hole 84 is set smaller than a width d2 of the engagement hole 83. |
