SHIMANO XTR Rd-M9100 Rear Derailleur Stealth Gray, Sgs 12 Speed

I've always had really good luck and liked the feel of the xtr derailers. My old 11 speed XTR was almost maintenance free for 4 years and felt better than my bikes with sram GX parts. This is no different. I also like the B screw adjustment line. I'm using it with a Sram 10-50t so I had to tune the B screw a bit more inboard than the 51T line suggested but a little experimenting got it dialed in. Shifts great just like my old 11 speed XTR did, nice crisp precise shifting. Very happy with it.

I managed to Completely snap my original XT derailleur on some logs awhile back on a ride and needed a replacement fast. Unfortunately all I could find that shipped fast was this XTR derailleur. It works great just like the XT but lighter, more expensive, and shinier.

The shimano 12 speed XTR derailleurs are great but suffer from a very bad flaw. I’ve been running both SRAM eagle and XTR 12 speed drives. Both great. The shimano shifts and runs slightly more smoothly than the the SRAM. The shimano cassette has a more progressive gear range. But... there is a major problem with the XTR: the clutch housing is not waterproof. Water can find its way into the clutch from the clutch lever seal and the clutch cover o-ring. Once water gets inside the clutch, it rusts and need to be replaced. I’d recommend lubing both these seals before Installing an XTR derailleur.

Converted form 10 speed to 12 speed drive train, full shimano components really needed to be used to get best shifting, tried KMC/sram changes but they do not shift as quietly or precisely as the shimano.