CNC Headtube – How Our MTB Frame Lugs Are Really Made

In Episode 6 of our MTB Frame Development series we visit Spantech to show how our lug design goes from a 3D CAD model to a fully CNC-machined part.

Spantech first caught our attention when they CNC-machined the one-piece crown for Intend — and with Manuel, who’s deeply involved in programming and machining and also a biker himself, it was clear they understand both the technical and real-world demands of bicycle parts.

In this episode we take a close look at:

How our FEM-optimised lug geometry is prepared for CNC machining

The transition from CAD to CAM and how toolpaths are defined

5-axis CNC machining, clamping strategies and tool choices

Weight reduction from raw aluminum block to finished lug

Machining times, roughing vs finishing, and where the real costs come from

We also explain why we intentionally chose a coarser finishing strategy:
It significantly reduces run time and cost — and we genuinely like the look of the visible tool paths. Not every surface needs to be perfectly smooth if it fits the character and function of the frame.

The lugs shown here are machined exactly as designed, without any cost-driven geometry changes yet. Now that the feasibility is proven, the next step will be to further cost-optimise the design in order to reach a sweet price point for the complete frame — without compromising strength, precision or aesthetics.

This series documents real development decisions, compromises and trade-offs — not marketing claims.