No longer available from the manufacturer. Requires upgrade to four sided (square) crank shaft assembly and new crank arms to fit the 4 sided (square) crank shaft

Crank shaft assembly comes with crank pulley, crank shaft, and right hand bearing. It is recommended to replace the left hand bearing when replacing the crank assembly. Left hand bearing is sold separately.

Crank shaft ends are six sided (hexagon) to mate with the six sided (hexagon) hole of the crank arms