If you, like a few of us old souls around the Competitive offices, are holding fast to your belief in the soul of mechanical shifting, Shimano hasn't abandoned you. Though the world may very well be moving towards 100% electronic drivetrains someday in the future, mechanical still makes a hell of a case for itself. With smooth lines, elegant finishing, and functionality beyond reproach, the redesigned mechanical Dura-Ace drivetrain calmly holds its own in this brave new world of wires, batteries, and display screens. It's fitting then, that the Dura-Ace FC-R9100 11-Speed Crankset also comes with the double chainrings that many roadies are loathe to abandon just yet. Call upon your granny gear when needed with this lighter, stronger version of a top-end classic, and embrace tried-and-true tradition of cables. Of course, in the even that you do decide to run electro-shifting, the crank's ring profile plays just as nicely with Di2 derailleurs.
Shimano didn't introduce any drastic changes to its proven four-arm design, but it did make a few subtle, deliberate changes to bring it up to the most modern compatibility standards. By widening the crank arm, Shimano was able to move the chainline 0.5mm outboard; this barely perceptible repositioning was just enough to give the crankset broader compatibility with shorter chainstays and the growing number of road bikes built for disc brakes.
The gram counters will be happy to learn that beefing up the crank arm didn't result in a change in weight. Instead, Shimano was able to carefully remove internal material where it wasn't needed, strengthening only the most crucial areas of the crank arms and actually reducing weight by around a claimed 7g over the previous generation. The Japanese brand calls this process Hollowtech II, but it could very well be sorcery for all we know. In addition, Shimano also slightly reshaped the chainrings' gear teeth profile to adapt it to the gearing on disc brake-equipped race bikes.
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.