Originally Posted by
Kontact
I doubt you are using the measurements correctly. There is no way that a 32 degree knee bend at a 45 degree heel angle goes to not being able to reach the pedals when you lower the heel 20 more degrees. You would still have about 20 degrees knee angle.
If your technique for measuring this sort of thing is not done right, your conclusions about how things work aren't very useful.
I have pretty large feet. The difference between 45 degrees and 20 degrees is quite a few centimeters. The 109% formula puts my seat around 6 centimeters too high. It's actually three centimeters higher that the Lemond method which is also too high.
Also using the measurements is just trigonometry. There's nothing mystical about it. I could have used made up values or just split the inseam value in two and the results would have been similar.