Head tube

Head tubes can use one of several size standards The head tube of a bicycle is sometimes designated by the fork steerer column it accepts.

This can lead to confusion, since head tube inside diameters are dependent on the headset standard.

The wide variety of integrated and non-standard, proprietary headsets that some frame manufacturers have created (and abandoned in some cases) makes listing all current and past head tube dimensions problematic.

The following table includes the most common sizes; nominal head tube diameters are assuming a 0.1-0.2 mm interference fit, which is what most head tube reaming cutters are designed to bore.

Adequate press fits are typically between 0.1 and 0.25 mm of interference.