Hi,

a few months ago I came up with the idea of using two well established formulas for seat post height and deriving the crank length from them : as follows :

1. Top of seat to centre of BB = 0.883 X your inseam* length
2. Top of seat to pedal at bottom of downstroke = 1.09 X your inseam* length

So, if you calculate your inseam and work out these two values, the difference between them is your crank length.

I never actually found anybody to confirm my idea and I did this out of common sense, however, taking into account that these are two well accepted formulas and that when I set up my bike to these specs I solved my knee problems, I think it works.

* write to me if you need instructions on how to measure your inseam.

cheers

claude