I tried a 54t (w/ 15t cog) for a while, but the torque puts a lot of strain on all the components and frame when sprinting or doing steep hills. Not to mention the stress on the knees when going downhill with no brakes. I ultimately decided to drop to 50t so as not to destroy the frame and components and save the big chainrings for when I can afford a real track bike. Interestly the 113mm bb cartridge was the first casaulty -- the 103 sugino bb replacement puts a lot less leverage on the bearings and has lasted quite well for a year now.