C4 Class, 1997/2018, Italy
History & Specifications
The company C4 was founded in February 1986 by Nicoletta and Marco Bonfanti in Italy and was a pioneer in the production of monocoque carbon frames. In 1996, C4 produced the world’s first production frame with a weight of 1000 g with the frame model “Class”. The carbon fork still featured a Cr-Mo steel steerer tube for safety reasons. The timeless Italian design of the 1997 frame was emphasized by building it with a 2018 Shimano Ultegra groupset. I made a point to only use black and charcoal colored parts. Individual parts such as the SR stem and the Campagnolo cable stops on the frame were anodized black. The C4 Class frame is NOS, all components except the saddle are new parts. I achieved my goal of keeping the overall weight under 7.50 kg without an expensive carbon wheelset. The bike is in unridden condition. More information about the history of C4 at the company website https://www.c4carbon.com/Azienda.
Frame size seat tube 57 cm center-top, top tube length 55.7 cm center-center, seat tube angle 73°, head tube angle 74°, weight 7.5 kg.