Let’s cut to the chase, because we all know that’s why you’re here. You want to know, gun to our head, which 12-speed mountain bike drivetrain would Mtbr choose: SRAM or Shimano?
Well, the answer is easy. While we’ll forever love and appreciate what SRAM did for modern mountain biking, ushering in the 1×12 drivetrain era and simultaneously killing off front derailleurs, when it comes to actual shifting, Shimano’s XTR offering simply works better than any of the Eagle options.
Shimano XTR M9100 Highlights
- Smooth and precise shifting, even under pedaling load
- Logical gear steps, specifically at extreme ends of the cassette
- 510% gear range covers virtually all terrain scenarios
- Multi-release function gives the ability to drop two gears with a single push
- 2-way release allows you to shift gears with lever push or pull
- Price: $1,700 as tested (not including brakes)
- Available now
So what defines “better”? Think about that friend who’s new to the sport and doesn’t yet understand the basic nuances of shifting. They don’t get that before you fully depress the shift lever you need to ever-so-slightly back off the gas in order to let your derailleur complete the shift. It’s a subtle art that seasoned mountain bikers have grown to understand and accept. It becomes embedded in our muscle memory. It’s not ideal, but it’s the way it is.
Well, actually, not anymore. See, with Shimano’s new XTR M9100 drivetrain, you can shift like an idiot. In fact, moving through gears while still mashing the pedals is the best way to shift this drivetrain. Because No. 1 XTR allows you to, and No. 2 that means you don’t have to sacrifice critical momentum.
This is all thanks to Shimano’s innovative Hyperglide+ system, which lets you combine those two critical riding activities when, for instance, you’re halfway up a steep AF, techy climb and a momentarily hesitation would invariably mean a dab, or worse. Not anymore. Just pedal and shift and go. It’s simple and the way it should be.
Combine XTR’s ability to shift flawlessly under high torque with Shimano’s approach to gear steps on what will be the most popular of the three new XTR cassette options (the 10-51 version tested here), and you basically know all you need to know about the latest XTR group. While Shimano and SRAM’s wide range cassettes are identical through the first eight cogs (10-12-14-16-18-21-24-28), Eagle positions its largest jumps at the end, going 28-32-36-42-50. The wide-range, 12-speed XTR cassette, on the other hand, runs 28-33-39-45-51. The key, of course, is that final shift (from the 42 to 50 on versus 45 to 51). One is abrupt and clunky. The other is smooth and crisp.
You can guess which Mtbr preferred. And, no, it’s not because Shimano one-upped SRAM with one extra cog tooth. Honestly, we didn’t even notice. We just noticed the quiet, smooth, and breathlessly precise way Shimano XTR M9100 moves your chain up and down. Every. Damn. Time.
Keep reading to learn more about our XTR test session, and stay tuned for an accompanying post on Shimano XTR four-piston brakes, XTR hubs, and some of the other components on this Yeti SB150 test build, which when added up has been one of the best all-around bikes Mtbr has ever ridden.
The Magic of Hyperglide+
To understand why we’re such big fans of XTR, it helps to understand how Hyperglide+ works. In a nutshell, the tooth shapes on the M9100 cassette guide the chain up and down the cassette, providing faster, smoother shifting in both directions. That’s combined with the M9100 HG chain, which features extended inner link plates that connect seamlessly with new chainring tooth shapes, keeping in contact with each tooth. That quiets side-to-side vibration and results in better drivetrain efficiency because you have improved chain engagement, stronger retention, and a smoother pedaling action.
Now, think about out-of-saddle shifting while under full pedaling load. Normally you wouldn’t. You’d hesitate, shift, and resume spinning. And if you did shift under load there would be a jerky feeling and loud clunking noises as the chain jumped from one cog to the next. Not with XTR. It’s smooth, quiet, and fast, making for the most pleasurable shifting experience we’ve had to date.
Controlling all the precise movement is a Shimano RapidFire Plus shift lever, which is claimed to offer lighter operation force and more versatility thanks to an I-Spec EV lever design that features greater flexibility in mounting for a clean and ergonomic cockpit. Indeed, Shimano says their latest XTR lever delivers 20% quicker shift activation with 35% less shifting operation force compared to XTR M9000. Mtbr obviously couldn’t precisely validate any of that, but we can say that the lever action is indeed quick and easy. No delays or tired thumbs here.
Related: Shimano XTR first ride review
Combine that with the multi-release and 2-way release functionality, and add in well-conceived ergonomics and small rubber grips on the paddles, and there’s a lot to love about these shifters. I actually shifted more just because it was such a pleasant (and reliable) experience. And because the second shift of the multi-release function requires a touch more input than the first, there were no accidental shifts.
Then there’s the whole gear steps thing. Instead of having to sometimes toggle between porridge too hot and porridge too cold, Shimano engineered reasonable gear steps where it matters most, at the top of the cassette when you’re likely in the hurt locker. Indeed, this addresses what was for me among the biggest issues with SRAM Eagle, that you often end up climbing in a gear that’s too easy because you don’t have a better option because the 42-tooth cog is too tall. But with Shimano XTR there’s a sweet spot in the 45-tooth cog — and when the trail does get steeper, the jump to the easiest gear is far smoother.
Durability and Dependability
Be honest. How many times have you had to adjust B tension on your SRAM Eagle group? The guess here is more times than you’d like. And how about that little red plastic set-up tool? Probably not your favorite tool.
Well, Shimano gets the nod here, too. They smartly printed a little mark on the back of the outer pulley cage that makes it easy to set B-tension without the need for a red plastic tool. More importantly, once set-up, I’ve yet to have to mess with the B-tension. This stuff has just kept working properly over a test session that’s entering its fifth month of regular use.
Nothing is Perfect
Outside the fact that it took Shimano way too long to bring this drivetrain to market, it’s hard to find too much fault here. Weight weenies may still decide to opt for SRAM XX1, which with its blingy carbon cranks and other fancy bits is a fair bit lighter (and more expensive). Indeed, XTR’s weight and cost is more in line with X01 Eagle, which is actually about 50 grams lighter if you add up the cranks, derailleur, chain, cassette, and shifter. I personally don’t care. I ride trail and enduro bikes, and prefer good shifting over saving an inconsequential amount of weight.
The other knock, and this one will be tough for some, is that the XTR cassette requires use of Shimano’s new Micro-Spline driver body, which utilizes 23 rectangular splines, allowing for use of a multi-piece cassette with a 10-tooth cog. The cassette employs what Shimano calls its Beam Spider construction, where a combination of aluminum (3 largest cogs), titanium (5 middle cogs), and steel (4 smallest cogs) are used for the best blend of weight savings, rigidity, and durability. And in case you’re curious, the 10-51 XTR cassette weighs 369 grams, or about 10 grams more than a 10-50 Eagle X01 cassette.
The issue with the Micro-Spline freehub requirement is that it has not been licensed to many other wheel makers yet, meaning DT Swiss, Mavic, Industry Nine and a few others are your only options at the moment. You can also purchase an XTR hub and build up your own wheel, which is what we did here, utilizing a set of ENVE M735 carbon wheels, which have been bombproof thus far.
Shimano XTR Verdict
No buried lead here. We told you our verdict in the second paragraph of this post. But in case you somehow missed it, the bottom line is that Shimano’s latest XTR and first truly purpose-built 1×12 drivetrain is awesome. And if it’s out of your price range, don’t fret; the XT and SLX versions that were released earlier this year are almost just as good.