Taiwan has been the center of the global bicycle supply chain for decades, and Taichung is at its heart. Many hub, drivetrain and component brands source machined parts from this region.
This guide covers how CNC bicycle hubs and small bike components are machined, which materials and finishes are common, and what to send when you ask for a quote.
Which bike parts are CNC machined
Forged or extruded blanks are often finished by CNC, and many parts are machined straight from bar stock. Typical CNC bike parts include:
- Hub shells (front and rear), including flange drilling and bearing bores
- Axles, end caps and spacers — typical CNC turned parts
- Freehub body parts and ratchet components
- Thru-axle and quick-release components
- Chainrings, crank parts, stems and small brackets
- E-bike motor and battery mounting parts
How a hub shell is machined
A hub shell combines turned features — bearing bores, the body profile, flange diameters — with milled and drilled features such as spoke holes, lightening pockets and logos. A common route is turning first, then finishing the flanges and spoke holes on a 4.5-axis mill, where the part can be indexed to drill holes around the flange in one setup.
Bearing bores are the critical features. Their diameter, roundness and alignment to each other decide how the wheel runs. Mark them clearly on the drawing as critical dimensions.
Materials and finishes
Aluminum alloys dominate bike components because of their strength-to-weight ratio, and they take anodizing well — which is how hubs get their colors. Alloy steel is used where wear or strength matters more, such as some axles and ratchet parts.
Anodizing adds a thin layer, so bores and threads that must fit precisely need to be planned for it. Tell us the anodizing color and which surfaces must stay bare.
Tolerances and inspection
We machine metal parts to a tolerance of 0.02 mm. For hub bearing seats, state the bearing you use and the fit you need, and we will review the critical tolerances with you.
What to send for a quote
- 3D model (STEP) and 2D drawing with tolerances and thread callouts
- Material grade and anodizing color
- Quantity for the first order and expected yearly volume
- Whether you need prototypes before production
About our shop
Chi Xin Technology is a CNC machine shop in Nantun District, Taichung, Taiwan, founded in 2022. We run 5+ CNC machines — 4.5-axis CNC machining centers and CNC lathes — and mainly machine aluminum alloys and alloy steel, with a metal tolerance of 0.02 mm. We also offer wire EDM and surface finishing including anodizing, and we export to customers in Europe and North America.
Frequently asked questions
Can you machine prototypes of a new hub design?
Yes. We machine prototypes as well as production runs, so you can test a design before ordering volume.
Can you anodize the parts?
Yes. We offer surface finishing including anodizing. Tell us the color you need when you request a quote.
Do you ship to Europe and North America?
Yes. We export to customers in Europe and North America.
