Shimano Dura-Ace FC-R9100 Crankset

Shimano Dura-Ace FC-R9100 Crankset

That Shimano Dura-Ace FC-R9100 Crankset is seven grams lighter than its predecessor is just the tip of the proverbial iceberg. This crankset sees changes just about everywhere.

First, one place it hasn’t changed is the 24mm thru-axle spindle. This will work in not only the BB-R9100 bottom bracket in the Dura-Ace group, but all modern outboard Shimano bottom brackets.

The arms have been changed. You still have the unique Shimano bolt circle diameter that allows you to set up both compact and standard chainring combinations. But the spider arms are a bit more asymmetric than in the past to better fight the forces you legs put on them. The spider position relative to the bottom bracket has also been revised, Shimano moved it minimally toward the bottom bracket for better chain alignment (in some cases, this might limit compatibility with Dura-Ace FD-9000 front derailleurs). The large chainrings have also been designed a bit differently, a bit larger, and thus stiffer. There are several chainring combinations: 50/34, 52/36, 53/39, 54/42, and 55/42, which runs from a traditional compact to a time trial-specific setup.

The tooth profiles have been revised. The shaping and cuts are designed to better accommodate the large jumps between small and large chainrings.

The crank arms themselves have been changed, with a design that looks fatter when seen from the side, but is still narrow to the wind when seen from the front. The arms come in a wide range of sizes, with 2.5mm jumps from 165mm up to 180mm. The chain line measures 43.5mm, which should work great with traditional road and cyclocross frames as well as with disc-brake road and ‘cross frames.

Weight for the Shimano Dura-Ace FC-R9100 Crankset is 609g with the 50/34 combination, 621g with the 53/39 set. The bottom bracket is not included with the crankset.