The Shimano Deore XT CS-M8100 is a wide-range 12-speed mountain bike cassette built around Shimano's HYPERGLIDE+ tooth profile and MICRO SPLINE freehub standard. Rider-tuned gear steps deliver smooth, precise shifting up and down the block — even under full pedaling load — making it one of the best-value performance drivetrains in mountain biking.

⚠️ Freehub compatibility: This cassette requires a Shimano MICRO SPLINE freehub body. It will not fit standard HG (Hyperglide) freehubs. Please confirm your hub before ordering.

Key Specifications

• Model: Shimano Deore XT CS-M8100
• Speeds: 12-speed
• Gear range: 10-51T (wide 510% range)
• Cog combination: 10-12-14-16-18-21-24-28-33-39-45-51T
• Freehub type: Shimano MICRO SPLINE
• Compatible chain: Shimano 12-speed HG chain (CN-M8100 / M9100 series)
• Weight: 470 g (16.6 oz)
• Color: Silver / Black
• Construction: Beam Spider with alloy carrier and alloy lockring

Technology Highlights

• HYPERGLIDE+: Redesigned shift ramps and pickup points allow fast, smooth shifts under load in both directions.
• MICRO SPLINE: Smaller, more widely distributed splines enable a 10-tooth top cog and limit cog damage on the freehub body.
• Beam Spider: Light, stiff construction reduces cassette inertia for faster acceleration and improved chain security.

Who It's For

Built for XC, trail, and enduro riders who want a tight mid-range for efficient pedaling plus a 51T bail-out gear for steep climbs. The CS-M8100 also meets Shimano's durability requirements for E-MTB applications, so it stands up to the higher torque of motor-assisted riding.

What's in the Box

• 1 x Shimano CS-M8100 12-speed cassette sprocket set (10-51T)
• 1 x alloy lockring

Condition & Shipping

• Condition: Brand new in retail packaging
• Ships from: Ontario, California (US domestic)
• Estimated delivery: 3–5 business days