SHIMANOXTR Sl-M9100 Trigger Shifters

This is an enormous drivetrain upgrade in terms of shifting feel. The downshifts are crisp and can move 4 gears, and the double upshift function is great feature.

Very good. It is quite "crisp" and not as smooth as a previous (and quite a few years back) XTR shifter, but it is very precise.I bought it to replace a SRAM shifter that came in my 2021 Santa Cruz Blur (I am not fond of the SRAM thumb shifters) and works like a charm with the SRAM real derailleur.

torn up box , wire a mess

I especially like the option to down shift two ways

Positive shifts, very smooth an precise

I've used the 12-speed XTR M9100 shifter for about 1 year. Shifting performance is flawless, solid, quick and butter smooth with excellent feedback so you KNOW you've shifted. Works in perfect harmony with the M9100 chain, crankset, rear derailleur and 12 speed cassette so you can shift quickly and easily under full load while climbing. One big problem: I've had two of these shifters fail after about 3-4 months normal use. The longer downshift lever misses "catches" and just swings with no resistance and no shift, intermittently, but once this starts, it doesn't change. The defect is an overly weak and brittle rocker spring, not user replaceable. This is the 10 cent part that breaks the $125 machine. Because I've had two new shifters fail this way, it's not a fluke. The picture attached shows where the spring breaks (lower arrow).

This XTR was both 11 and 12 speed compatible with the flip of a switch, but Shimano has removed the switch and this updated version is 12 speed only.

Feels notchier and less precise than the previous M9000. Accomodates 11 or 12 speed with the adjustment of a hex nut. Trigger position is worse for my hand, making my thumb travel down and around the lever rather than cleanly under it. Seems worse ergonomically and less efficient.