SHIMANO M9100 XTR DRIVETRAIN REVIEW
THE RIGHT AMOUNT OF EVERYTHING FOR EVERYONE
Words by Joe Mackey | Photos by Nic Hall
In the summer of 2018 Shimano finally unveiled the 12-speed drivetrain we all hoped was coming, the new XTR group. In true Shimano fashion, they took their sweet time and went through all the refinements to uphold Shimano’s XTR legacy. There were even some surprises with this drivetrain, including a 2x option with 10-45 cassette. I’m still not sure who that was made for since no one has released a 2x-compatible mountain bike in the last four years, but I’m glad to see Shimano sticking to their guns and offering riders who hold onto their bikes for more than three seasons a worthwhile drivetrain upgrade. The new Shimano XTR M9100 group was one of the most anticipated product launches in recent years and over time it has lived up to every bit of hype. If you missed our first look video and interview with Shimano from the product release camp, check it out here!
• New freehub standard in the form of MicroSpline
• 1x and 2x (gasp!) options
• 10-51 and 10-45 cassettes
• Updated I-SPEC IV cockpit integrations with brakes, shifters and dropper remotes
• 24mm spindles on all cranks with 1x and 2x (38-28 tooth combinations)
• HyperGlide+ provides incredibly smooth shifting under load
For the deep dive tech feature where we highlighted all the new features and components in detail, check the link here.
I’m not going to dive into all the new tech with the M9100 as that was meticulously covered by Chilidog at the Shimano XTR launch back in June of 2018, so we’ll just get right to our experiences over the last year and a half riding multiple XTR groups on different bikes. This review is focused solely on the 1x version as we haven’t even ridden a bike with a front derailleur mount in a number of years, but we’re confident it works well since Shimano front derailleurs are quite precise, if you’re into that sort of thing.
There are a couple things to watch for when installing the new Shimano XTR M9100, but overall, it is not a complex experience. B-tension is key to success with the 9100 drivetrain and luckily the guide makes that pretty eassy. Shimano built in a handy little line on the back of the derailleur, indicating where the 51-tooth cog should line up with 13-tooth pulley. This makes B-tension adjustments much easier in the work stand and even on the trail. SRAM includes a little plastic tool for a similar purpose with their Eagle kits, but Shimano’s approach is more practical as you don’t have to worry about losing or forgetting to pack the indicator tool since it’s built in.
The M9100 XTR kit comes with Shimano’s polymer-coated shifter cable. I opted for a standard steel shifter cable as the outer layer on the polymer cables can subtly peel and bunch up in the housing, causing the drivetrain not to function properly.
My first ride on the Shimano XTR M9100 raised the bar for me on what to expect from a drivetrain in terms of shifting performance, and it has not let me down since. The XTR shifter has a very pronounced reassuring feel when I push the paddle, always letting me know it’s engaging. Compared to SRAM Eagle, instead of a “click” like a computer mouse, there is a slightly harder push to get the shifter to engage. However, that push of the shifter results in a more affirmative and solid shift as well. This shifter feel carries over on Shimano’s XT level group but not quite as smooth when initially pushing into the lever. The grippers on the shifter paddle were a much-needed upgrade over the previous generation. The tactile feeling is our favorite on the market and offers grip and comfort.
The shifting performance and feel are completely linear with the XTR. Whether I was standing or sitting, the derailleur, chain and cassette worked seamlessly. Out of the saddle I could shift under load and not worry about missing gears or having the chain skip. The ability to shift with my thumb or forefinger was a bonus in my mind, as it is a practical touch to give riders more options.
I could talk all day about how smooth the Shimano XTR M9100 shifts, but the real magic is in the cassette. I’m not talking about the 51-tooth cog. While SRAM and Shimano will throw percentages all day long and do fancy “maths” there isn’t a huge difference on the trail between 50 and 51. But Shimano does offer a much more intuitive and natural feel in the steps between the 10-51 gears. The jumps in gears are subtle, gradual, and almost perfect. Depending on chainring size, I was able to maintain a consistent cadence and pedaling motion on gradual and steep pitches of trail. I have always struggled with SRAM’s Eagle cassette and the jumps in gears. Shimano addressed this in a way that makes it an easier drivetrain to ride. If you regularly find yourself shifting up and down thinking, “I just can’t quite find the right gear,” you’ll love the Shimano cassette.
Throughout almost all of our testing this drivetrain didn’t require any maintenance, other than the occasional chain cleaning and lubing. The drivetrain stayed reliable and quiet until one of the bikes started to get some creaking from the rear derailleur. This was the clutch getting dry and making a pretty horrible noise when shifting up. I pulled off the clutch cover and lubed the sides of the clutch and put the cover back on and didn’t have any more issues moving forward.
While there are tons of great performance benefits to boast about this drivetrain, MicroSpline has been a tough one for me stomach. I am all about progression of product, but another freehub standard just further creates a divide between brands and how it negatively impacts the cycling community. Inaccessibility to parts and issues with cross compatibility are just a start.
The Wolf’s Last Word
At this point it’s safe to say that in my opinion, the Shimano XTR M9100 is the best 12-speed drivetrain currently available. But that doesn’t necessarily mean it’s for every rider. Cost will be a deterrent for many, but Shimano has been able to trickle down almost the same shifting performance to their M8100 XT drivetrain at a reduced cost. I’d say SRAM’s Eagle XX1 group has done a great job of positioning itself as the “racer’s” drivetrain. It shifts a bit easier and quicker and is lighter than XTR. It is also more expensive, doesn’t last as long and doesn’t have the long-term reliability in our opinion. If you want a robust, reliable and crisp shifting drivetrain with the best Shimano has to offer, then XTR is for you. If you want a drivetrain that is a touch more affordable what I would suggest is going with an XT cassette with an XTR shifter and rear derailleur. Regardless of which way you go or what level of Shimano drivetrain you go with, you’ll have the confidence to know it all started as cutting edge XTR componentry at one point. This kit is certainly the best one we’ve ridden yet from Shimano and is one we hope to see on more test bikes in the future.
Derailleur – $256.99,
Trigger Shifter – $129.99,
Cassette – $379.99 – 389.99,
Chain – $69.99
Derailleur – 240 grams,
Trigger Shifter – 195 grams,
Cassette – 370 grams,
Chain – 262 grams
Disclosure: Our team selects all of the products we review and do so with honesty and objectivity in mind. Some of the products we receive come directly from Competitive Cyclist, who also value our readers and have offered them a 15% discount on their first purchase by using LOAMWOLF15. Through this program we may also receive a small commission at no cost to you. Thanks for your support, TLW.
Shifting under load!
The shifting performance is superior in every sense
Natural steps make finding the right gear easy
Set it and forget it
Clutch can be loud and creaky in dry conditions but remedied by lube
Doesn’t have a derailleur lock like SRAM for removing rear wheel
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