| 摘要 |
A bicycle includes a stem extending downwardly from a handle, and a crank mechanism interconnecting the stem and a head tube. The crank mechanism includes a frame fixed on the head tube, a lever pivoted to a front end of the frame and extending uprightly therefrom, a crank pivoted to the rear end of the frame and extending uprightly therefrom, and a coupler member pivoted to an upper end of the crank and movably connected to an upper end of the lever so as to permit co-movement of the lever, the crank and the coupler member relative to the frame and so as to permit frontward and rearward movement of the handle together with the stem relative to the head tube. A locking unit is selectively and movably connected to two of the frame, the lever, the crank and the coupler member, and is operable between locking and unlocking positions.
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