The Dura-Ace CS-R9100 is Shimano's flagship 11-speed road cassette, engineered for elite road and criterium racing where every gram and every shift matters. Combining titanium sprockets, carbon fibre carriers, and Shimano's refined HyperGlide tooth profiling, it delivers the fastest, most consistent shifting available in a road cassette. The 11-28T ratio suits riders who want a versatile range across flat to moderately hilly terrain without sacrificing top-end speed.

Highlights

• Titanium large cogs: the five largest sprockets are machined titanium, saving significant weight without compromising durability under load.
• Carbon fibre/alloy carriers: multi-material spider assemblies bond groups of cogs into rigid subassemblies, reducing flex for more precise engagement.
• Refined HyperGlide tooth profile: updated tooth geometry compared to the CS-9000 speeds up shifts and smooths transitions across all sprocket combinations.
• Nickel-plated steel small cogs: the six smallest sprockets are steel for long-term wear resistance where engagement forces are highest.
• 11-speed precision: engineered to pair with the full Dura-Ace R9100 groupset for seamless front and rear shifting.

Construction

Shimano redesigned the R9100 cassette from the ground up compared to the CS-9000. The two largest cogs are joined as a pair on a shared carrier, and the next three cogs share a second spider assembly — both carriers use a combination of aluminium and carbon fibre to maximise stiffness-to-weight. The remaining six smaller cogs are individual nickel-plated steel sprockets mounted directly to the freehub body. The result is a cassette that weighs just 193g in the 11-28T configuration.

Compatibility & Fit

Designed for Shimano 11-speed road drivetrains. Fits all standard Shimano HG (HyperGlide) 11-speed freehub bodies. Compatible with Shimano Dura-Ace R9100, Ultegra R8000, and 105 R7000 11-speed rear derailleurs and shifters. Requires an 11-speed chain (e.g. Shimano CN-HG901-11). The 11-28T gear range (11-12-13-14-15-17-19-21-23-25-28T) suits road and criterium racing on flat to rolling terrain.