Manufacture method for bicycle's crank - with solid head and tail using a shorter process at lower cost

摘要

A manufacture method for bicycle's crank with solid head and tail is provided in this invention. A metal is extruded as a bicycle's crank prototype when it is placed in a mold. The head part of this crank prototype is formed as the first solid part with a slot hole in the center. After the second metal material is stuffed into the tail part of the crank prototype, a crank product with solid-type head and tail and internal cavity at the central can be forged or stamped. With the above manufacturing method, the processes, the production cost and the labor hours can be reduced, and therefore the production rate can be increased.