I ride an Open U.P. with Ultegra derailleurs & shifters, Easton crank, Reynolds 650b wheels, Lauf fork, Rene Herse or Vittoria tires (depending on terrain). I keep up with many riders that are in better shape than I am. Maybe they are just nice, or maybe good equipment can give you a bit of an edge? Or maybe I am just more tired after? I am not beaten up after though with the Lauf fork and the Open frame at least. I am not a podium finisher, but I am in the competitive pack.