That's right, 11.5 pounds or 5,2 kg. I saw this in the Cannondale booth at the Tour of California. The fellow standing next to it was the guy who built it. How'd he do it? Check it out:
One piece carbon fiber saddle where the shell wraps around and becomes the rails.
Tiny strand of carbon fiber going from nut to nut on the seat post binder.
Segmented carbon fiber tube used as cable housing.
A kevlar/carbon blend non-oversized (25.8mm) handle bar. The stem looks like a split, hollow aluminum tube.
Carbon fiber with no cam release mechanism.
Carbon crank from a German company named THM Carbones. Carbon fiber chainrings. The guy said they were raced in a criterium. Also, hollow pin chain with machined out side plates. This seems more like a gimmick than a technology. Carbon fiber is basically abrasive plastic that fails catastrophically and probably isn't a fantastic power bearing drive train component. I am open to be proven wrong.