Shimano M9100 XTR Groupset Review - First Impressions

I have been riding my new S-Works Epic HT frame since October last year. I’ve been enjoying the impressively awesome ride, but the bike has always been something of an incomplete work in progress. The 11 speed M9000 XTR / XX1 drivechain had been starting to show its age, the once bullet proof shifting no longer occurring the instant you clicked the paddle. Also I wasn’t taking full advantage of the frames 148mm "Boost" rear wheel spacing. I have been running spacers so I could use my existing rear wheel and I was in constant fear of losing one of the little red washers while fixing a puncture out in the wild, or of one rolling under the floor boards of the shed during an evening maintenance session.

With the arrival of Spring and with the new race season on the horizon it was time to finish the job and fit a groupset the frame deserved. I spent a long time debating the pro’s and con’s of Shimano M9100 XTR vs SRAM XX1 Eagle. Then just as I was about to commit along came SRAM AXS! Hands-up I ordered an electronic XX1 AXS groupset! I pulled out of the purchase in the end because this summer I have some rides planned that exceed the 10 hour predicted battery life. I could purchase a spare battery, but I know from the occasions when I forget to charge my Garmin or Mobile phone, that one day I would reach for the bike to go out for a ride and realise I’d forgotten to charge the battery. It’s a new world problem I could do without.

I’ve always preferred Shimano shifters to SRAM’s thumb/thumb layout, so M9100 XTR was my preferred option. However, Shimano faced a number of problems with the roll out of the new groupset. Gone was my preferred lightweight and racey 11 speed option. The original chain quick link wasn’t compatible with the two new Absolute Black Oval Chainrings I had hanging in the shed. (No problems with the new link supplied with my groupset.) Also not all the options were available when I came to order, so I was forced to make some compromises. The 12 speed 10-45 cassette was out of stock so I had to go 10-51 with a long cage rear mech. That is 100 g of extra weight right there compared to my current set-up and I don’t feel like I need or will use the extra gear. Also Shimano introduced  yet another new I-Spec configuration with the M9100 groupset so I couldn’t mate the new shifter with my existing Shimano brakes. (In the end I bought the new brakes as well – more on that later!)

First things first though was to sort a 148mm boost rear wheel. Strada Handbuilt Wheels built my existing Light Bicycles rim onto a DT Swiss 240 rear hub. I’ve been running a Stans 3.30 rear hub for the last 8 years and there is definitely a better pick up from the DT Swiss freehub and there is the opportunity of upgrades to improve this further.  Including the center lock adaptor for the disc rotor the 800g weight is only ever so slightly heavier than my original set-up despite the extra hub width. I'd be lying if I said I could feel any noticeable stiffness or performance benefit from the wider hub. 

I enjoyed an evening bolting the new components to the bike. Everything was straight forward, although I spent as long threading the rear brake hose through the internal routing as I did building the rest of the bike! Grrr! The next morning I hit the local trails with the boys for a Sunday blast that included a lot of climbing and fast flowing singletrack decents that would test the full range of gears.

The shifting is instantaneous as to be expected from a top tier groupset like XTR. Each gear is actioned with much more of a definite ‘clunk’ at the lever than the silky ‘click’ of the previous M9000. In fact I would describe the lever feel as quite SRAM like. This is no problem and I soon got used to it. I think the double downshift however does have a much nicer feel. At the other end the chain travels seamlessly up the cassette. Coming back down the gears is noticeably smoother than older groupsets. Shimano have introduced what they call Hyperglide 2 and you can feel when quickly dropping a bunch of gears that the chain doesn’t just tumble to the smaller sprocket, but smoothly purrs its way across the gears providing a much more consistent pedal stroke. It’s very impressive.

The standout feature of the groupset for me however is the brakes! I wasn’t going to replace the brakes, but after a number of issues with my previous M9000’s I decided to invest in the new stoppers. I never found the old brakes to be very consistent. The bite point would vary every time you pulled the lever – sometimes long, sometimes short. I’d bled them dozens of times, but this characteristic had always remained. The lever pull of the M9100 is the same EVERY time you pull the lever. I cooked the pads on one descent, I could smell the burning rotors, but the lever pull never changed.

I finally have that new bike feeling the excellent S-Works frame deserved. Shifting is crisp, the bike is silent beneath me and everything gets on with its job flawlessly and without complaint. Silence is another characteristic of the DT hub with its almost inaudible freewheeling. There is also that massive extra 51 tooth emergency gear should I ever need it! Coupled with the improved handling of the S-Works frame this really is definitely the best bike I’ve ever owned. I can’t wait to get her into her natural habitat – the race track!