SHIMANO Ultegra CS-R8101 / CS-R8100 12-Speed Road Cassette (11-34T) - OEM Bulk

Upgrade your road or gravel bike with the genuine Shimano Ultegra CS-R8101-12 / CS-R8100 12-Speed Cassette. Featuring Shimano's pro-tier HYPERGLIDE+ technology and a versatile 11-34T climbing range, this lightweight 12-speed cassette provides lightning-fast, silent, and seamless gear changes even under maximum pedaling torque.

Key Specifications

• Brand: SHIMANO
• Series: Shimano Ultegra R8100 Series
• Model Options: CS-R8101-12 / CS-R8100-12
• Speed: 12-Speed
• Gear Combination (11-34T): 11-12-13-14-15-17-19-21-24-27-30-34T
• Freehub Compatibility: Fits standard Shimano/SRAM 11-Speed Road HG freehub bodies AND Shimano 12-Speed Road freehubs
• Technology: HYPERGLIDE+ (Precision-shaped tooth profiles for continuous power transfer)
• Material: Nickel-Plated Steel Cogs with Lightweight Anodized Aluminum Spider & Lockring
• Average Weight: Approx. 345g
• Condition: 100% Authentic Brand New
• Packaging: OEM Bulk (Protective Polybag)

Why Choose Shimano Ultegra CS-R8101 / CS-R8100?

1. Pro-Level HYPERGLIDE+ Shifting

Precision-engineered shift ramps and tooth shaping guide the chain smoothly up and down the cassette without requiring you to back off pedaling pressure, ensuring maximum efficiency during sprints and steep climbs.

2. Lightweight Alloy Spider Architecture

Anodized aluminum spider carriers hold the largest cogs firmly, increasing torsional stiffness under heavy loads while shaving valuable grams compared to 105-level cassettes.

3. Versatile 11-34T Climbing Range

The 34T low cog offers an easier gear ratio for spinning comfortably up steep mountain passes, making it the ideal choice for endurance road riding, steep gradients, and gravel setups.

Compatibility & Technical Notes

• Drivetrain Fitment: Fully compatible with all Shimano 12-speed road drivetrains (Ultegra Di2 R8150, Dura-Ace Di2 R9250, 105 Di2 R7150, and 105 Mechanical R7100).
• Chain Compatibility: Requires a Shimano 12-speed HG road/MTB chain (e.g., CN-M8100, CN-M9100, CN-M7100, CN-M6100).
• Freehub Fitment: Mounts onto existing standard 11-speed Shimano/SRAM road HG spline freehubs without needing specialized freehub tools.

Frequently Asked Questions (FAQ)

Q: What is the difference between CS-R8100 and CS-R8101?
A: CS-R8101-12 is Shimano's updated revision of the CS-R8100-12 cassette. Both share identical 11-34T gear ratios, HYPERGLIDE+ shifting technology, weight, and 12-speed compatibility.

Q: Will this fit on my standard 11-speed road wheels?
A: Yes! Shimano 12-speed road cassettes feature a recessed rear spider design that mounts directly onto standard 11-speed Shimano/SRAM road HG freehub bodies.

Q: Is this authentic Shimano?
A: Yes, 100% genuine Shimano Ultegra components sourced directly through authorized OEM supply channels.

Q: Fast Domestic Shipping?
A: Yes, all orders ship directly from our US warehouse for quick delivery.