This is the bike I finished the Ironman World Championships in Hawaii on last Saturday. Never been done on a fixie. I know why - unbelievable effort.
Basic Schwinn Madision, with carbon clip-ons, a Zipp 1080 front wheel, Thompson seatpost, Ritchey stem. Standard brakes and everything. I had to put the brakes back on the bike to make it legal to compete, but never really used them - what is the point?