Shimano Micro Spline
Shimano · 12-speed · min 10T
Quick answer
Shimano’s 12-speed MTB driver (XTR/XT/SLX/Deore), 10 t smallest cog. Trainer-side bodies have historically been scarce — check availability. 10 trainers offer a Shimano Micro Spline body.
Trainers offering this freehub
- Tacx NEO 3M(sold separately)
- Tacx Flux 2 Smart(sold separately)
- Tacx Flux S Smart(sold separately)
- Elite Suito-T(sold separately)
- Elite Direto XR(sold separately)
- Tacx NEO 2T(sold separately)
- Elite Justo 2(sold separately)
- Elite Avanti(sold separately)
- Elite Justo(sold separately)
- Elite Rivo(sold separately)
Drivetrains that need this freehub body
- Shimano Deore12-speed · M6100 · CS-M6100-12
Shimano 12-speed MTB needs Micro Spline, which most trainers do not ship and some cannot take at all. This is the most common reason an MTB will not mount on a direct-drive trainer.
- Shimano SLX12-speed · M7100 · CS-M7100-12
- Shimano XT12-speed · M8100 · CS-M8100-12
- Shimano XTR12-speed · M9100 · CS-M9100-12
Frequently asked questions
Shimano’s 12-speed MTB driver (XTR/XT/SLX/Deore), 10 t smallest cog. Trainer-side bodies have historically been scarce — check availability. It accepts 12-speed cassettes with a smallest cog of 10 teeth.
10 trainers offer a Shimano Micro Spline body: Tacx NEO 3M, Tacx Flux 2 Smart, Tacx Flux S Smart, Elite Suito-T, Elite Direto XR, Tacx NEO 2T, Elite Justo 2, Elite Avanti, Elite Justo, Elite Rivo. It is sold separately on all of them.
On every trainer in our database the Shimano Micro Spline body is a separately-bought accessory, not included in the box.
Shimano Micro Spline accepts 12-speed cassettes (min 10T). Shimano cassettes are the native match; check cross-brand compatibility before buying.
These drivetrains use a cassette that mounts on a Shimano Micro Spline body: Shimano Deore (12-speed), Shimano SLX (12-speed), Shimano XT (12-speed), Shimano XTR (12-speed). Read it off your rear derailleur — the groupset name is printed on it.
Yes on the trainers listed above — you unscrew the existing freehub body and fit the Shimano Micro Spline one (a cassette tool and a few minutes). On trainers that don’t list a Shimano Micro Spline body, conversion isn’t supported.