THE FACT ABOUT MOTORIZED BIKE PARTS THAT NO ONE IS SUGGESTING

Crankshaft is meant to convert linear (up and down) motion of piston into rotational motion. Forged steel is accustomed to make this part and it can be machined by CNC equipment and well balanced to precision. There's two most important designs for stems: quill stems (that are ‘L’-shaped and drop directly in to the headset) and threadless stem