Today on the way into work, I stopped at the LBS and bought a new pair of SPD shoes, made by Specialized. They are a revelation. My feet have been in such pain that the pain has inhibited me from pedaling hard. With the pain gone, I'm able to ride harder than I imagined possible. I was zooming up hills in high gear. I was almost in tears from the joy and also from the sorrow of all the years of pain I have endured. I hope this proves to be the reason I conk out after an hour on the bike. Pain causes fatigue!