The threaded shaft is made of durable heat treated steel and this unit uses double bearings for strength inside of an anodized aluminum housing. This unit must have a 1/2-20 or 7/16-20 crank bolt thread to be used.
Can be used on all crank hubs and bearing support hubs that use six 3/8" bolts on a 2.782" bolt circle.
Racer can pick between 7/16 or 1/2 threads from the drop down menu.