01
Bar bore out of round
A 31.8 mm bore that measures 31.75 mm at the split line will not grip a carbon bar evenly. The rider feels it as a creak on every climb, and the bar is marked before the first service.
Custom machined components
CNC Bike Parts
Stems, clamps, seat collars and drivetrain hardware machined from 6061-T6, 7075 or Ti-6Al-4V. Bar bores and steerer bores held to ±0.005 mm so the assembly goes together on the first try.
6061-T6 / 7075±0.005 mmAnodizing in-houseNo MOQ12-hour quote
16Simultaneous 5-axis centers
±0.005 mmTypical machined tolerance
3–5 daysParts ship after release
99.99%Qualification rate
Where bike parts go wrong
Four failures we see on incoming drawings
Most rejected stem and clamp batches fail for the same reasons.
02
Steerer bore too tight
Press-fit bores machined at nominal size seize on the steerer tube. Forcing them on distorts the stem body, and the headset preload never settles. Reaming after anodizing adds a second operation and a second setup.
03
Face cuts not parallel
If the two clamping faces are not parallel within 0.02 mm, the gap closes unevenly. One bolt takes the load. On a hard landing the thread pulls through the softer half of the assembly.
04
Anodize changing the fit
Hardcoat anodizing builds 25–50 μm per surface. Threads and bores masked by hand come back undersized on the batch that mattered. The parts are already plated, so the scrap cost is the full part.
How we hold those numbers
Machining strategy for stems and clamps
One setup for the bores, one setup for the faces, and a plating plan written before the first chip.
Setup and datum control
Bore and face in the same setup
A stem body is a block with two perpendicular bores. If you machine the bar bore in one setup and the steerer bore in another, the two axes drift apart by whatever the vise repeats to. On a 5-axis center we cut both bores from a single datum, so perpendicularity stays inside 0.02 mm across the run.
For 7075 and 6061-T6 we leave 0.15 mm on the bore walls for a finishing pass at low feed. That removes the cutter deflection from the roughing pass and gives the anodizer a uniform surface to work with.
- 1Single-datum boringBar bore and steerer bore cut without re-clamping the part.
- 2Finishing allowance0.15 mm left on walls, removed at low feed to kill deflection.
- 3In-process probingBore diameter checked on the machine before the part leaves the fixture.
Material and finish
Pick the alloy before the finish
6061-T6 is the default for stem bodies: weldable, cheap to anodize, and strong enough for a 100 g part. When the wall gets thinner than 3 mm or the rider is above 100 kg, 7075-T6 buys roughly 40% more yield strength, but it anodizes to a darker, less uniform color and cannot be welded.
Hardcoat anodizing adds 25–50 μm per surface. We mask threads and press-fit bores before plating, then re-check the critical diameters after. Clear anodize for color matching, hardcoat where the part sees rock strikes. Laser marking sits at 1.5 mm minimum character height so batch codes stay readable after blasting.
- 16061-T6Default for bodies and clamps. Even anodize, low cost.
- 27075-T6Thin walls and high load. Harder to finish uniformly.
- 3Ti-6Al-4VBolts and pivots where corrosion and fatigue matter.
Alloy selection
Which material for which part
Pick the row that matches the load case, not the price list.
| Alloy | Best for | Watch out for |
|---|---|---|
| 6061-T6 | Stem bodies, clamps, seat collars | Yields first when walls go under 3 mm |
| 7075-T6 | Thin-wall stems, high-load pivots | Anodize color shifts between batches |
| 6082-T6 | Bar ends, mounts | Similar to 6061, slightly better corrosion |
| Ti-6Al-4V | Bolts, axles, suspension pivots | Slow to cut, cost per part is high |
| 17-4PH | Dropouts, high-stress brackets | Needs heat treatment after machining |
| 304 stainless | Hardware, brackets, spacers | Heavier than aluminum for the same load |
What we machine
Bike components and the processes behind them
One shop for the machined part, the finish and the inspection report.
01
Stems and clamps
Bar bores from Ø25.4 to Ø35 mm, steerer bores 1-1/8 in and 1.5 in tapered. Face cuts held parallel within 0.02 mm.
02
5-axis machining
16 simultaneous 5-axis centers for undercuts, angled bolt bosses and one-piece clamp geometry that would need three setups on a 3-axis mill.
03
CNC turning
16 mill-turn centers for axles, pivot bolts, headset spacers and bottom bracket cups. Turned and milled features in one cycle.
04
Surface finishing
Anodizing, powder coating, bead blasting and brushing. Threads and press fits masked before plating.
05
Rapid prototyping
One-off stems and brackets for fit checks. Same tolerances as production, so the geometry you test is the geometry you buy.
06
Inspection and reporting
CMM reports on request for bore diameter, perpendicularity and face parallelism. Raw material certificates traceable to the heat number.
Machining envelope
Tolerances and sizes we quote every day
| Feature | Capability | Notes |
|---|---|---|
| General tolerance | ±0.005 mm | Typical on critical bores and faces |
| Bore diameter | Ø6 – Ø60 mm | Bar bores, steerer bores, pivot holes |
| Face parallelism | 0.02 mm | Stem clamping faces |
| Surface finish | Ra 0.8–1.6 μm | As-machined on bore walls |
| Fine finish | Ra 0.2–0.8 μm | Where a bearing or seal rides |
| Maximum part size | 4,000 mm | Frame jigs and fixtures |
| Batch size | 1 to 10,000+ | No minimum order quantity |
Why buyers keep the file here
Numbers we are held to
15Y
Machining since 2011
Three wholly-owned plants in Dongguan and Singapore. The same team quotes the job and runs the job, so the tolerance you agree on is the tolerance on the inspection sheet.
±0.005 mm
Tolerance that survives plating
Critical diameters are re-checked after anodizing. If the coating pushed a bore out of spec, the part does not ship.
127
High-precision CNC machines
16 simultaneous 5-axis centers, 12 four-axis mills, 16 mill-turn centers. Capacity to shift a run forward without moving the deadline.
12 h
Quote and DFM analysis
A quotation plus a free manufacturability review inside 12 hours. Thin walls and deep bores flagged before you cut metal.
ISO
Four certifications
ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022. Documented process control, not a wall poster.
NDA
Designs stay yours
Uploads are secure and confidential. A non-disclosure agreement is available before you send the first STEP file.
100%
Inspection before shipment
Raw material check, in-process monitoring and final inspection on every batch. Reports on request.
7,600 m²Manufacturing space
150Technicians on staff
<2%Historical late-delivery rate
0Minimum order quantity
What the industry asks for
Requirements we deliver against
MTB stems
Bar bore roundness inside 0.02 mm, face parallelism inside 0.02 mm, hardcoat anodize masked at threads.
- ±0.005 mm
- Ra 0.8–1.6 μm
- 100% inspected
E-bike drivetrain
Motor mounts and pivot plates machined from 6061-T6 and 7075-T6, with material certificates traceable to the heat number.
- 6061-T6
- CMM report on request
- 3–5 day ship
Suspension pivots
Pivot bolts in 17-4PH and Ti-6Al-4V, turned in one cycle with the flange, then bead blasted for a uniform finish.
- 17-4PH / Ti-6Al-4V
- Ø400 mm rotary
- Turned + milled
Cockpit hardware
Faceplates, spacers and clamps in 6061-T6, anodized in clear or black, with laser marking at 1.5 mm minimum character height.
- Anodized
- Laser marked
- No MOQ
FAQs
Questions engineers send before ordering
What tolerance can you hold on a bar bore?
±0.005 mm on the diameter is our standard for a 31.8 mm bore, measured on the machine and again at final inspection. If the bore is split, we cut it as a closed bore and slit afterwards so the clamping gap stays even.
Below 20 mm bore diameter the limiting factor becomes the finish, not the size. Tell us the fit class and we will pick the reaming or boring strategy to match.
Should I use 6061-T6 or 7075-T6 for a stem?
6061-T6 for anything with walls at or above 3 mm. It anodizes evenly, costs less and is easier to source in the sizes you need.
7075-T6 when the wall goes thinner or the load case is severe. It gives about 40% more yield strength, but the anodized color shifts more between batches and it cannot be welded.
How does anodizing affect my dimensions?
Type II anodize builds 5–15 μm per surface. Hardcoat builds 25–50 μm per surface. Both grow the part outward, so a bore gets smaller and a boss gets larger.
We mask threads and press-fit bores before plating and re-check critical diameters after. If you have a bore that must stay at nominal, say so on the drawing.
Can you machine a one-off stem before I commit to a run?
Yes. There is no minimum order quantity, so a single prototype and a 10,000-part run go through the same process. Production can start within 24 hours of release.
Prototypes are machined to production tolerances. The geometry you test on the bike is the geometry that comes off the production line.
What files do you need for a quote?
A STEP or IGES file plus a 2D drawing with the critical dimensions, tolerances and finish callout. If there is no drawing, send the sample and we will scan it to pull detailed dimensions.
Quote and DFM analysis come back within 12 hours. Thin walls, deep bores and features that need a second setup get flagged in the same reply.
How do you inspect a bike component before it ships?
Raw material check on arrival, in-process monitoring on the machine, then a final inspection of every part. CMM reports are available on request for bore diameter, perpendicularity and face parallelism.
We hold a 99.99% qualification rate. Parts ship in 3–5 days after the run is released.
Do you sign an NDA for new frame or cockpit designs?
Yes. Uploads are secure and confidential, and a non-disclosure agreement is available on request before you send the first file.
Your files are not shared outside the quoting and machining team. That matters most in the prototype stage, before a design is public.
Send your bike part drawing
Upload a STEP file and a 2D drawing. You get a quotation and a manufacturability review within 12 hours, and a prototype can run without a minimum order quantity.
12-hour quote±0.005 mm100% inspectionNo MOQNDA on request
