Update March 2008:James posts about the 3195 gram road bike that German cyclist Günter Mai built up. That's just a hair over 7 pounds for a complete bicycle. According to this VeloNews article, Mai started with a set of $15,000, 850-gram Lew wheels, custom built just for him and his 150 pound weight. After the wheels were delivered, Mai literally shaved another 30 grams from the wheels by shaving material off the axle end caps, replacing the steel freehub pawls and hub spacers with titanium, and using tapered carbon/boron axles and full ceramic bearings. He also carved off some of the freehub splines that are not needed with the six-speed cassette he uses. Read the article in VeloNews for the full frame and component specs on this lightest road bicycle. It's interesting that even components such as derailleurs were custom rebuilt by Bicycle Tuning Parts in Germany.
The M2Racer Light Bike weighs in at 7.91 pounds. They started with a Litespeed Ghisallo frame and put the lightest components they could find for this lighest bicycle. Check out the carbon cassette, the custom downtube shifters, paper-thin custom saddle, drilled out brake levers and old school cable routing.
IMPORTANT: Please post comments for this article at the new CYCLELICIOUS 2.0 version of this page.