IF you already have a bad knee, 5mm can be like an inch!
Here's a link I started quite awhile back about my experience.
Post# 110 gave some later results-
http://www.bikeforums.net/showthread.php/361045-Are-Your-Cranks-Too-Long?highlight=
Last edited by Bill Kapaun; 03-24-13 at 08:36 AM.