At the Eurobike show in August 2007 Shimano introduced the carbon fibre Dura-Ace FC-7800C crankset. Originally this crankset was designed to be compatible with the Dura-Ace 7800 series. However, with the introduction of the new Dura-Ace 7900 series this year Shimano has decided to adapt this crankset to be compatible with the new 7900 group instead. Furthermore, a special chainring set will be available that will make this crankset also compatible with Dura-Ace 7800.
As announced recently, the new Dura-Ace 7900 has a further refined front shifting performance and trimming of the big chain ring is no longer needed. These features were made possible by a new chain ring design and new front derailleur of Dura-Ace 7900.
FC-7800C has an aluminum core to realize a lightweight yet very rigid construction. By using this technology, Shimano developed a crankset that combines the best of both materials. The aluminum frame ensures a stiff set-up for optimal power transfer while using carbon saves weight. Weight of this crankset (including bottom bracket) is 715 grams. This state-of-the-art crankset will be available in gear combinations 53/39T and 52/39T in crank arm lengths 170, 172.5 and 175mm as an after-market product from the end of December 2008.