Shimano Ultegra CS-R8101 12-Speed Cassette

Product Overview

Hyperglide+ performance. Ultegra refinement. The sweet spot of Shimano's 12-speed range.

The Shimano Ultegra CS-R8101 is the 12-speed cassette from Shimano's legendary Ultegra R8100 series—the groupset trusted by enthusiasts, weekend warriors, and competitive amateurs worldwide. Engineered to deliver nearly identical performance to flagship Dura-Ace at a significantly more accessible price point, this cassette represents the "sweet spot" in Shimano's 12-speed ecosystem.

Whether you're sprinting for the line, grinding up alpine climbs, or chasing a personal best on rolling terrain, the CS-R8101's Hyperglide+ technology delivers seamless, lightning-fast shifts—even under maximum pedalling force.

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Key Features

⚡ Hyperglide+ Technology – Revolutionary Shifting Performance

• Seamless shifts both up and down the gear range – technology that revolutionised off-road shifting is now transforming road cycling

• Shift without backing off – even during maximal efforts up a climb or racing a friend, riders no longer need to ease up to perform a shift

• 1/3 faster shifting compared to 11-speed Shimano groupsets

• Smooth shifting even when standing on the pedals

🎯 Refined 12-Step Gear Combination

• Available in two gear ratios to suit your terrain:

  • 11-30T: 11-12-13-14-15-16-17-19-21-24-27-30T

  • 11-34T: 11-12-13-14-15-17-19-21-24-27-30-34T

• First eight cogs – closely spaced for natural, comfortable progression

• Provides peak efficiency and accelerating performance for every racing situation

🔧 Premium Construction

• 12 steel sprockets with nickel-plated finish for hard-wearing corrosion resistance

• 2 lightweight aluminium spider arms for reduced weight and increased rigidity

• Anodised aluminium lockring included

• Refined evolution of the 12-speed road cassette

🛞 Universal Freehub Compatibility – Upgrade Without Hassle

• Compatible with both SHIMANO 12-speed and 11-speed road freehub bodies

• Larger driving cogs maximise drivetrain efficiency while retaining compatibility with existing Hyperglide freehub bodies

• Perfect for upgrading existing 11-speed bikes to 12-speed

🏆 Unbeatable Value

• Nearly identical performance to Dura-Ace at a significantly more accessible weight-to-price ratio

• The "sweet spot" in Shimano's 12-speed ecosystem

• A good compromise between efficiency, weight and price

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Specifications

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Compatibility

✅ Compatible With:

Shift/Brake Levers:

• ST-R9250, ST-R9270 (Dura-Ace)

• ST-R8150, ST-R8170 (Ultegra)

• ST-R7120, ST-R7170 (105)

• ST-RX820, ST-RX610 (GRX)

• ST-R8060, ST-R9160, ST-R9180

Rear Derailleurs:

• RD-R9250 (Dura-Ace)

• RD-R8150 (Ultegra)

• RD-R7150 (11-34T only)

• RD-R7100 (11-34T only)

• RD-RX820 (11-34T only)

Chains (Recommended):

• CN-M9100 (XTR)

• CN-M8100 (XT / Ultegra)

• CN-M7100 (SLX / 105)

• CN-M6100 (Deore)

Groupsets:

• Shimano Dura-Ace R9200 / R9270

• Shimano Ultegra R8100 / R8170

• Shimano 105 R7100 / R7150

• Shimano GRX RX820

Freehub Bodies:

• SHIMANO 11-speed road freehub bodies

• SHIMANO 12-speed road freehub bodies (HG L2)

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Ultegra vs 105 vs Dura-Ace: Which Cassette Is Right for You?

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What Riders Are Saying

"Good cassette... A good compromise between efficiency, weight and price. High-quality product. Ideal resistance for climbers." — Mantel Customer

"Great shifting performance, high shifting speed and smooth shifting even when you're standing on the pedals." — Mantel

"Just fitted before I embarked on a French Alpine trip. Made life much easier on the long climbs and the extra 4 teeth are making a great difference." — Deporvillage Customer

"The CS-R8101 represents the 'sweet spot' in Shimano's 12-speed ecosystem, offering nearly identical performance to Dura-Ace at a significantly more accessible weight-to-price ratio." — Evo Cycles

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What's in the Box

• Shimano Ultegra CS-R8101-12 Cassette × 1

• Shimano aluminium lockring × 1

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Technical Notes

⚠️ Freehub Compatibility: Compatible with both SHIMANO 11-speed and 12-speed road freehub bodies

⚠️ Derailleur Compatibility: The 11-34T version requires a medium or long cage rear derailleur – check compatibility with your specific model (RD-R7150, RD-R7100, RD-RX820 support 11-34T)

⚠️ Chain Compatibility: For optimal performance, use with SHIMANO HG 12-speed chains (CN-M9100 / M8100 / M7100 / M6100)

⚠️ Installation: Requires a cassette lockring tool and chain whip. Torque lockring to 40 Nm

⚠️ Maintenance: Nickel-plated finish offers corrosion resistance – clean regularly with degreaser

⚠️ Lifespan: Typical lifespan 5,000–8,000km depending on riding conditions and maintenance

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About Shimano Ultegra

Ultegra has long been the choice of serious amateur racers and enthusiasts who demand professional-level performance without the professional-level price tag. When developing the Ultegra R8100 series, Shimano took a holistic and 100% performance-oriented approach—because great speed means great responsibility. Faster than ever before, the 12-speed groupset delivers unparalleled control and comfort anytime, anywhere—whether in an amateur race, on the hunt for a personal best, or on a companionable ride. The CS-R8101 cassette embodies the "Science of Speed"—the pursuit of ultimate performance through advanced materials, precision engineering, and obsessive attention to detail.

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Experience Ultegra-level performance. Add the Shimano CS-R8101 to your cart today!