Very iterative process over 2.5 years.
He watched me ride for miles. He measured me.
Then we rode different off the shelf bikes that supposedly “fit” my height— Specialized, Giant, Canyon, etc, and compared their geos with my body. We discussed how each of the off the shelf options felt during rides, different situations, etc. I didn’t realized there is so much variation between different brand geos in say a “small” or a “medium” frame.
Then I rode different crank lengths and we agreed on 160mm as ideal for my body and leg length. Stem discussions, stack height discussions, seat post height discussions. We went back and forth for quite a while with slight modifications to really dial it in.
And then he built the frame and that was pretty much it.
Here is a screen shot of my geos from a video he made explaining it to me.
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