As always, the spider is great to look at. But like with any proprietary tech, Shimano's top-secret BCD may inspire a healthy dose of skepticism. Rest assured that Shimano has its reasons. With the Dura-Ace 9100 crankset, you can run anything from a 50-34 combo to a 55-42 just by swapping chainrings, chain, and repositioning your derailleur. No need for a spider swap or an entirely new set of crank arms. Effectively, this means your bike can be a TT missile one weekend, a hill climb champ the next, and versatile all-rounder for the time in between. If you’re a privateer racer, or a self-sponsored athlete, it makes a whole lot of sense.
A top-of-the-line classic continues to keep up with the times
Redesigned crank arm accommodates disc brake frames
Chainline and tooth profile adapted to gearing on disc race bikes
Reduction in weight without a sacrifice in strength
Allows for huge range of gearing options with a single crank
Shimano proves there's still a place for aluminum crank arms at cycling's most elite levels
