Been following this site for a couple of years and must say that I have learned more from this site than any other site and most books. This brings me to my question, I recently bought a Serotta Tri-Colorado for Tri/TT from a Pro cyclist friend of mine. Since he did not worry about running after his events he has a 56 big chainring installed. Now I am no Miguel Indurain and I know that with a 650C bike you need to run different gears than on a typical 700C rig. I am seriously considering a 54 or should I stay with the 56. Any thoughts? I recently read a note from John Cobb about this subject as well.