 Lines follow those of current aluminium design |
 Cross-section shows carbon-fibre shell |
 Spider insert ensures accurate axle location |
Shimano has unveiled details of the new FC-7800C carbon fiber Dura-Ace crankset, which allies an aluminum core with a carbon-fibre shell to creat a lightweight and rigid construction.
The company has resisted using carbon-fibre for the crankset until now, since its tests indicated that using carbon-fibre alone may allow a weight reduction but at the expense of rigidity.
The aluminum frame ensures accurate, reliable location for the pedal eyes, axle and chainring bolts, while the carbon-fibre shell maximises crank arm rigidity while saving weight. The weight of this crankset (including bottom bracket) is 709 grams with a 10percent gain in stiffness over the FC-7800 aluminum Dura-Ace crankset.
The FC-7800C crankset employs Shimano’s proven Hollowtech II hollow crank arm technology with integrated bottom bracket. It uses the FC-7800 bottom bracket bearings and the left crank arm features the same installation technology as current Shimano XTR. The crankset will be available in 53/39 and 52/39 chainring combos on a 130mm BCD with crankarm lengths of 170, 172.5 and 175mm.
The carbon crankset has already seen race action at the Tour de France where it was ridden by Michael Boogerd (Team Rabobank) and Markus Fothen (Team Gerolsteiner). They were apparetly pleased with the combination of lighter weight, optimal rigidity and an attractive design.
FC-7800C will be available as an aftermarket product from spring 2008
