Reference
Cassette/Freehub Compatibility
Compatibility between drivetrain components is one of the most expensive areas to make a mistake. Buying a cassette that doesn't fit the freehub means...
Compatibility between drivetrain components is one of the most expensive areas to make a mistake. Buying a cassette that doesn’t fit the freehub means returning it and trying again.
Freehub bodies #
The freehub is the splined drum on the rear hub that the cassette slides onto. There are 4 main types:
| Freehub | Hub bodies | Cassettes that fit | Speeds |
|---|---|---|---|
| HG (Hyperglide) — Shimano/SRAM 8/9/10/11s | Most older / mid-range | Shimano HG cassettes 8/9/10/11s, SRAM 8–11s NX | 8–11 (with spacer for older) |
| HG L (longer) | 11s road specific | 11s road only | 11 |
| SRAM XD / XDR | Modern SRAM | SRAM XD (MTB) / XDR (road); 10–28 to 10–52t | 11–12 |
| Shimano Microspline (MS) | Newer Shimano XT/XTR/SLX MTB | Shimano 12s MTB | 12 |
| Campagnolo (CN) | Campy hubs | Campy 9–12s | 9–12 |
Practical compatibility rules #
- HG 11-speed cassettes and below all work on the same HG freehub (just different spacer setups).
- SRAM Eagle 12-speed (10–50, 10–52) requires an XD freehub. Cannot fit HG.
- Shimano 12-speed MTB (XT/XTR M8100/M9100) requires Microspline. Cannot fit HG or XD.
- Shimano 12-speed road (Dura-Ace R9200, Ultegra R8100) uses HG L (yes, road 12-speed and MTB 12-speed are different freehubs — frustrating).
- Mixed-brand drivetrains sometimes work, sometimes don’t:
- Shimano 11s shifter + SRAM 11s NX cassette: works (shares HG cog spacing).
- SRAM 12s shifter + Shimano cassette: usually does not work (different cog spacing on most combos).
- Shimano 12s MTB shifter + 11s SRAM cassette: works (shifter has HG mode; check exact shifter compatibility).
- Replacing a freehub body to change standards is possible on most modern hubs (DT Swiss, Industry Nine, Hope, Chris King, Shimano centerlock). On lower-end hubs, the freehub may not be replaceable.
Chain compatibility #
| Chain speed | Use with cassette of same speed? | Cross-brand? |
|---|---|---|
| 8s | Yes | Yes (Shimano/SRAM/KMC interchange) |
| 9s | Yes | Yes |
| 10s | Yes | Yes |
| 11s | Yes | Generally yes within road or MTB groups; some mismatch |
| 12s Shimano | Shimano 12s only | Generally NOT cross-compatible with SRAM Eagle 12s |
| 12s SRAM Eagle | Eagle only | Some KMC chains marked “Eagle compatible” |
Wheel hub upgrade decision #
If you’re moving up cassette speeds and find your current freehub doesn’t support the new cassette, options are:
- Swap freehub body (if your hub supports it) — $40–150.
- Get a new wheelset.
- Stay at your current speed.
Always check freehub compatibility BEFORE buying a new groupset.