White Industries Eno Eccentric hub. Done. Not that big a deal. Not that much work. He could probably keep his cranks and just get a SS chainring. Really not a big deal. Don't know why people are freaking out in here. Yeah, he could go buy an entry level steal fixed gear. But if he wants a nice carbon road race fixed gear, then the Madone will be fine.

I'd first check to make sure the dropouts on his Madone aren't carbon -- I can't remember if they are, and which year they started that, etc. The WI ENO hub might chew up his carbon dropouts if he's got them. Otherwise, just build a rear wheel around a WI Eccentric ENO and you're good to go.

Also, pet peeve of mine: people thinking/assuming riding fixed puts more stress on your frame, cranks, chain, etc. It does not. This "myth" is really annoying to me. The forces exerted when you "mash" or skid are not any more than any hard-effort standing start or sprint effort on a freewheel drivetrain. His carbon road frame is fine to fun fixed.