Bicycle frame part making method, involves placing tubular blank in innersurface of mold, heating tubular blank to working temperature, and injecting high pressure fluid into tubular blank

摘要

The method involves placing a tubular blank (30) in a mold (2) such that the blank is surrounded by an inner surface of the mold. The blank is heated to a working temperature ranging from 200 to 500 degree Celsius. A high pressure fluid is injected into the blank to permit expansion and permanent deformation of the blank to an extent that an outer surface of an expanded tube abuts against and conforms to the inner surface.