Jan Heine made some interesting comments about crank length in Vintage Bicycle Quarterly ( A 400K Brevet ). He commented about the fact that with shorter crank arms you can lower the Bottom bracket height , get a better cornering more stable bike and have the additional advantage of being able to continue pedaling thru the corners without fear of kissing the pavement , not to mention you also save your knees from the stress of longer cranks. I remeber reading somewhere that in the 50's the Randoneurs typically used crank lengths of about 165mm and smaller gear ratios.
I can also recall that this long crank thing has been tried before by the Professional racers again I think it was in the 50's or 60's and they moved back to more knee forgiving lenghts after a few years. What does anyone know about this?