Method for manufacturing a bicycle rim

A method for manufacturing a bicycle rim comprising the steps of:

• forming a first bar of material and a second bar of material by extrusion;
• rolling and cutting:
• a section of the first bar of material made into an arched section of material (unfinished external ring) and cut from the first bar of material, a section of the second bar of material made into an arched section of material (unfinished internal ring) and cut from the first bar of material, the unfinished external and internal rings having a C-shaped structure, a roller extending into the unfinished internal ring and tightly abutting against an inner periphery of the unfinished internal ring to prevent the unfinished internal ring from being shrunk during rolling;
• trimming:
• excessive portions of the unfinished external and internal rings being cut from by trimming;
• assembling:
• the unfinished external and internal rings being assembled and interconnected to each other;
• pressing:
• pressing the assembled unfinished external and internal rings to promote a connection between the unfinished external and internal rings;
• welding:
• the ends of the unfinished external ring being welded and connected to each other, and the ends of the unfinished internal ring being welded and connected to each other to from a rim structure;
• and
• grinding:
• grinding and removing any roughness of the rim structure and the bicycle rim being finished.