— A Complete Guide to Cassette & Hub Compatibility
When choosing a bike hub or wheelset, one of the most common questions we get is:
“Will my cassette fit this hub?”
Freehub standards differ between Shimano, SRAM, and Campagnolo systems — and choosing the wrong one can lead to installation issues.
This guide explains the key freehub types used in today’s cycling industry and how Koova hubs are designed to ensure wide compatibility.
🔹 Shimano Freehub Systems
1. Shimano HG (Hyperglide) Freehub
The most common standard for Shimano and many SRAM 10–11 speed cassettes.
▪ Variants of HG:
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MTB 10S HG (35mm) – Used for Shimano 8/9/10-speed mountain cassettes.
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Road 11S HG (36.8mm) – Slightly longer version for Shimano 11-speed road cassettes.
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When installing a 10-speed road cassette on this type, a 1.85mm spacer is needed.
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Different manufacturers make small adjustments to the HG length, but the spline pattern remains the same.
2. Shimano Microspline
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Designed for Shimano 12-speed MTB groups (Deore, SLX, XT, XTR)
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Features 23 smaller splines
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Allows 10T smallest cog
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Not compatible with HG freehubs
(Koova Microspline version is currently in development.)
🔹 SRAM Freehub Systems
1. SRAM XD
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Used for SRAM 11/12-speed MTB (GX, X01, XX1)
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Shorter body (~34mm) with a threaded interface
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Enables 10T smallest cog
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Not compatible with Shimano HG
🟢 If your cassette says “XD Driver” or starts at 10T, choose the XD freehub.
2. SRAM XDR
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Used for SRAM 12-speed Road / Gravel systems (Rival, Force, Red eTap)
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Slightly longer (~37mm) than XD
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XDR cassettes fit directly
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XD cassettes can fit with a 1.85mm spacer
🟢 If you ride SRAM 12-speed road or gravel, select the XDR freehub.
🔹 Campagnolo (CP) Freehub
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3 wide splines, unique Campagnolo pattern
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Only fits Campagnolo cassettes (Chorus, Record, Super Record)
(Koova CP version coming soon.)
🔹 Single Speed (SS) Freehub
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Narrow body (≈28mm)
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Fits single sprocket and lockring🟢 If you run a one-speed setup, choose the Koova SS hub.
🔧 Final Thoughts
Understanding freehub standards helps you avoid confusion and ensures perfect drivetrain performance.
Koova hubs are engineered for precision, durability, and cross-brand compatibility — whether you ride mountain, or single speed.
Not sure which cassette you have?
Send us a photo or model number — our Koova support team will help you choose the right freehub body.