Shimano Ultegra R8100 Cassette 12s

Shimano Ultegra CS-R8100 12-Speed Cassette (11-30T or 11-34T)

Premium 12-speed performance that delivers near-Dura-Ace shifting refinement at a far more accessible price point. Hyperglide+ technology provides exceptionally quick, seamless shifts—even under full power—while the smart gear steps keep cadence smooth whether racing, training, or tackling big climbs.

Available in two versatile ratios:

• 11-30T ? Tighter steps for racing, fast group rides, or flatter terrain where close ratios shine.
• 11-34T ? Extra bail-out gear for steep gradients, loaded touring, sportives, or riders who simply want easier climbing without sacrificing top-end speed.

Suited perfectly to Ultegra R8100 mechanical or Di2 groupsets, and a popular high-mileage choice among Dura-Ace owners for everyday wheels.

Key Highlights

• Hyperglide+ for lightning-fast, precise shifts under maximum load
• Refined tooth profiling ensures quieter running and excellent chain retention
• Lightweight construction: nickel-plated steel cogs on dual aluminum spiders
• Backward-compatible with standard Shimano 11-speed HG road freehubs (also fits 12-speed bodies)

Technical Specs

• Model: CS-R8100
• Speeds: 12
• Available Ranges & Cog Sizes • 11-30T: 11-12-13-14-15-16-17-19-21-24-27-30 • 11-34T: 11-12-13-14-15-17-19-21-24-27-30-34
• Average Weight: 291 g (11-30T) / 345 g (11-34T)
• Freehub Body: Shimano HG (compatible with 11-speed road HG and all 12-speed road freehubs)
• Material: Nickel-plated steel sprockets + aluminum spiders
• Chain Compatibility: Shimano HG 12-speed (e.g. CN-M8100)

A standout choice for serious road cyclists wanting top-tier shifting feel and versatile gearing without the full Dura-Ace cost.

Teeth 11-30
ICSR810112130
Real weight 295 g

Teeth 11-34
ICSR810112134
Real weight 350 g