Shimano CS-R8101 Ultegra 12 Speed Cassette

Step up to the next level of shifting precision and drivetrain efficiency with this 12-speed cassette engineered for road and gravel riders seeking high performance and reliability.

Why youll appreciate it

• Featuring the Hyperglide+ sprocket design, this cassette enables seamless up- and down-shifts even under full pedalling load so you dont have to back off when shifting during a sprint, climb or intense effort.

• Designed for 12-speed compatibility, the gear range options (such as 11-30T and 11-34T) give you the flexibility to match your terrain, riding style and cadence preference.

• Constructed with a rigid alloy sprocket carrier and steel sprockets for a balance of lightweight components, durability and consistent performance.

• Compatible with HG-Spline L2 or HG-Spline L freehub bodies, meaning it supports modern 12-speed systems while retaining compatibility with certain 11-speed hubs.

• Reported weights are approximately 291 g for the 11-30T variant and 345 g for the 11-34T variant competitive for its class and purpose.

Ideal for riders who

• Ride at high intensity whether thats racing, training or long efforts where gear changes matter.

• Want a cassette that supports both road and gravel applications with modern gearing flexibility.

• Value a drivetrain feel that is smooth, responsive and engineered for the demands of performance riding.

What it means for your ride
With this cassette installed, youll feel sharper transitions, smoother shifts and better overall drivetrain responsiveness. Whether climbing steep grades, attacking breakaways or riding long distances, the CS-R8101 helps maintain momentum and control so you can focus on your ride, not your shifting.

Pro tip for installation
Ensure the freehub body is clean and properly greased, install the cassette with the correct lock-ring torque, and pair with a compatible 12-speed chain. After the first ride, check lock-ring tightness and re-inspect after a few hours of riding to confirm everything has bedded in smoothly.