How we draw a frame from a fit sheet

We don’t start from a size. We start from Maya’s fit sheet: saddle height 742, setback 68, reach to bars 512, bar drop 64, and a note that says six hours on gravel.

From body to tubes

Saddle height and setback give us the seat tube and the seat angle. Reach and drop, minus the stem and bars she likes, give us the reach and stack. That’s the frame she sits on.

Then the handling

Where and how she rides decides the rest: longer chainstays and a calmer head angle for loose, long days, and clearance for 50 mm tyres. Maya signed off the drawing on a Tuesday. The tubes were cut on the Thursday.