The Shimano Dura-Ace CS-R9100 is the pinnacle of 11-speed road cassette engineering, delivering fast, precise shifting for competitive road and criterium riders who demand every gram and every millisecond. The 12-25T range keeps gearing tight and cadence consistent on flat to rolling terrain, making it the choice of sprinters and aggressive road racers.

Highlights

• Titanium large sprockets: The five largest cogs are machined from titanium, shaving weight without sacrificing the stiffness needed for crisp shifting under load.
• Nickel-plated steel small sprockets: The six smallest cogs use nickel-plated steel for long-term durability in the high-wear zone where you spend most of your riding time.
• Carbon fibre and alloy spider construction: Cogs are grouped into subassemblies on lightweight CFRP and aluminium alloy spiders, adding structural rigidity and reducing overall cassette weight.
• Optimised sprocket profiling: Each cog is precision-profiled for Shimano's 11-speed HyperGlide chain engagement, delivering fast and accurate shifts in all conditions — even under load.
• Individual cog replacement: The modular subassembly design allows individual sprockets or pairs to be replaced rather than the entire cassette, reducing long-term running costs.
• System integration: Designed as part of the complete Dura-Ace R9100 groupset, optimised for use with Shimano RD-R9100 rear derailleurs and CN-HG901 11-speed chains.

Construction

Shimano groups the sprockets into subassemblies: the two largest titanium cogs are paired on a single carbon/alloy spider, a further trio of titanium cogs sit on a second spider, and the six smaller nickel-plated steel cogs mount individually. This tiered construction minimises weight at the large-cog end where titanium delivers the greatest benefit, while using durable steel where tooth wear is highest.

Compatibility & Fit

The CS-R9100 is an 11-speed cassette designed for Shimano standard HG freehub bodies. It is compatible with all Shimano 11-speed road drivetrains — both mechanical (R9100) and electronic Di2 (R9150) — as well as Shimano-compatible 11-speed systems. Chain compatibility includes Shimano CN-HG901 and other Shimano 11-speed road chains. The 12-25T range (12-13-14-15-16-17-18-19-21-23-25T) suits flat to rolling road riding and criterium racing where close ratios and high cadence are prioritised.