1. Mixing 11-speed and 12-speed cassettes The classic mistake. Shimano 12-speed cassettes require a Micro Spline freehub body, incompatible with standard HG.
The rule : always check freehub body / cassette compatibility.
2. Wrong bottom bracket standard BSA, Press-Fit BB92, BB86, T47... A Shimano crankset can fit multiple standards, but not with the same bottom bracket.
The rule : identify the frame standard BEFORE ordering.
3. Rear derailleur cage length A GS (medium cage) derailleur doesn't handle the same range as an SGS (long cage).
The rule : check the total capacity of the derailleur.
4. Brake/lever compatibility Shimano changed the lever ratio between series. A BL-M8100 lever isn't optimised for an older generation calliper.
The rule : lever and calliper from the same series.
5. Centre Lock vs 6-bolt discs The rule : check the hub standard before ordering discs.
How L'Atelier helps Ask questions like:
"What cassette range is the RD-M8100-SGS compatible with?" "What bottom bracket for a BB92 frame with XT M8100 crankset?" The assistant answers with the exact source from the dealer's manual.
What is your machine worth? Estimate in 2 minutes. Free account to see the range — first detailed report on us.
