Is there a good reference for the equations used to calculate a frame geometry from someone’s fit measurements?
no. the best such equations could do is get you a ballpark estimate. the human body is too variable for a purely mathematic objective formula to work.
two ways to find the right fit. 1) Ride lots and listen to your body (this presupposes that people are able to listen to what their body is saying and then translate it to a workable solution. 2) Find a smart experienced fitter and let them do their thing.
bikes and bike fit is really pretty simple. i think people complicate it much more than it actually is. now, bike design. that’s a different story. designing a bike that fits, and rides like a race bike should ride, is a lot harder.
Ballpark estimates are what I’m curious about. I’m just interested in how fitters calculate their values. I’m being nerdy.
for the super nerds among us: read the coni manual. in the original italian, if you can. this is pretty much the final word in race bike fit/design (and it came out in 73, i think).
There are formulas out there. Check out Colorado cyclist http://www.coloradocyclist.com/bikefit/
and
Competitive cyclist:
http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO