On Test | Shimano SLX M7100 1×12 Drivetrain & M7120 4-Piston Brakes

Just a few months ago, Shimano unveiled the latest components to receive the 12-speed trickle-down tech from its flagship XTR M9100 groupset. And in a surprising (but somewhat needed) move from the Japanese brand, Shimano actually launched both Deore XT M8100 and SLX M7100 at exactly the same time.

We’ve already had plenty of time on the latest XT gear, and you can read more about the M8100 groupset in our launch piece here. We’ve had less saddle time with the new SLX M7100 drivetrain and brakes, which is a shame, because at a third of the price of XTR, this new SLX groupset is absolutely bonkers value for money.

We’ll be changing that though, after Shimano Australia sent us out a full Shimano SLX M7100 1×12 drivetrain and M7120 4-piston brake set for a proper long term test on home soil. Yieww!

shimano slx m7100 12-speed 1x cassette 10-51t
Shimano takes the SLX groupset up to 12-speeds!

New Shimano SLX M7100 – What’s The Skinny?

Just like XTR and XT, the latest SLX groupset also moves to 12-speed, with both 1×12 and 2×12 drivetrain options. And yes, Shimano is still making front derailleurs (*insert surprise emoji*). There’s a humongous 10-51T cassette, which uses the new Micro Spline freehub standard that we’ll get onto in just a bit. You can also get a smaller 10-45T cassette option, while a new modular crankset system allows you to easily swap between 1x and 2x direct-mount chainrings.

You’ve got more options with brakes, with both 2-piston and 4-piston callipers available. There’s also a redesigned master cylinder that gets the mid-mount bar clamp and the I-SPEC EV system for bolting a 12-speed shifter to the right brake lever, or Shimano’s MT800 dropper remote to the left brake lever.

shimano xtr m9100 1x12 10-51t cassette drivetrain
Shimano debuted its 12-speed XTR groupset last year, with XT and SLX following this year.
giant trance 29 advanced pro shimano xtr m9100 dvo
We’ve been pummelling the XTR M9100 groupset on our Giant Trance 29er long term test bike, and it’s been absolutely faultless.

How Does It Compare To XT & XTR?

Aesthetically and functionally, the new SLX groupset shares A LOT in common with XTR and XT – this stuff looks the absolute business! It is a bit heavier though – Shimano claims an SLX groupset is 148g heavier XT, and 513g heavier than XTR. But it’s also a helluva lot cheaper. Here’s the current Australian pricing for a groupset made up of a 1×12 drivetrain & 4-piston brake set;

The price advantage is perhaps even more impressive when you consider just the 1×12 drivetrain on its own, with SLX coming in at less than a third of the price of XTR ($592.90 vs $2015.04). That ain’t exactly small change!

To see how the performance fares in the long run, we’ll be getting the SLX groupset bolted up to one of our test bikes shortly. But before we do that, let’s take a closer look at the individual components that make up this groupset, and how they compare to both XT and XTR.

Shimano SLX M7100 Crankset

shimano slx m7100 12-speed 1x crankset
The new SLX crankset moves to a modular direct-mount chainring system.

The main news with the SLX crankset is its move to a direct-mount chainring system, instead of the four-bolt design of old. This allows for a modular setup that can easily change between a 1x and 2x setup. The arms themselves are still hollow alloy, and Shimano retains the 24mm steel axle. Thankfully, there are no new BB standards here. Shimano is offering the SLX crankset in a variety of lengths and chainline options, and it sells the chainring separately so you can choose the right size for your bike.

The crankset is where most of the weight difference is with XTR. A lot of this is due to the chainring, which instead of being a single piece of machined alloy, is made with a forged alloy spider and a bolt-on outer chainring that’s made from steel. While heavier, the steel teeth should actually last longer. It’s worth noting that those bolts aren’t meant to be undone though – they use a special torx key and are actually glued in place. Why this system? It means Shimano can manufacture just a single forged alloy spider to save costs, and simply attach different size outer chainrings as needed.

Shimano SLX M7100 12-Speed Shifter

shimano slx m7100 12-speed 1x shifter
12-speed clicky device includes tiny steel lasso as standard.

Clicking through the gears is a 12-speed right hand shifter, which uses the familiar dual-paddle design. Though the SLX shifter misses out on the rubber panels found on the pricier XT and XTR units, it still receives traction grooves for improved haptics. You can get the SLX shifter in a standard band clamp version (shown here), though it’s also available in a direct-mount I-SPEC EV option that sees it attach directly to the right hand brake lever.

One thing the SLX shifter does miss out on is the double up-shift that you get with the XT and XTR models, which is a bummer as we really like that feature. Oh and for those five people reading this, yes, Shimano does make a left-hand version of this shifter for the 2×12 setup. It’s actually a bit different with just a single Mono Lever design, which we’re actually quite intrigued to try out at some point!

Shimano SLX M7100 12-Speed Derailleur

shimano slx m7100 12-speed 1x derailleur sgs
The SLX mech comes in two versions; a long cage version for 1×12 setups with the 10-51T cassette, and a shorter cage option for 2×12 setups with the 10-45T cassette.

Sharing a very similar shape to the XTR 12-speed derailleur, the SLX mech gets a duller, but still very classy titanium-grey finish. The overall architecture is almost identical, with a one-way Shadow Plus friction clutch providing chain security. The clutch is adjustable internally, and you can also flick it off for taking the wheel out of the bike. Further quietening the drivetrain is a rubber bump stopper on the outside of the outer cage.

Compared to XT and XTR, the SLX mech downgrades from bearings to plain bushings for its 13T jockey wheels, and it also loses out on some of the higher-end materials, which adds a bit of weight. Of note is that there are two versions for this mech; M7100 (for a 1×12 setup with the 10-51T cassette) and M7120 (for a 2×12 setup with the 10-45T cassette). To help with setup, there’s a machined guide line on the inside of the jockey wheel cage to help you align the upper pulley with the largest cassette sprocket. It’s a bit like the red plastic SRAM Eagle setup guide, though Shimano has cleverly integrated the guide into the mech itself.

Shimano SLX M7100 10-51t Cassette

shimano slx m7100 12-speed 1x cassette 10-51t
There’s more weight in the SLX cassette due to a greater number of steel sprockets.

The workhorse of the SLX M7100 12-speed groupset is its huge 10-51T cassette. Using less exotic materials compared to its more expensive siblings, the SLX cassette relies on eleven steel sprockets, with the largest sprocket made from alloy. It still gets a forged alloy central spider, which holds onto the seven largest cogs, though the spider receives less machining compared to the XT 12-speed cassette. Here’s how the weight compares between SLX, XT and XTR;


Just like XTR and XT, the SLX cassette receives Shimano’s Hyperglide+ tooth profiling, which in our experience creates essentially fault-free up and down-shifting, whether you’re hard on the power or not. It is really impressive stuff, and is one significant advantage that Shimano currently has over SRAM.

One potential disadvantage though is the Micro Spline freehub body standard, which is necessary to accommodate the smaller 10T cog. At present, this special freehub still isn’t hugely available beyond DT Swiss, Industry Nine, Mavic, Bontrager, Roval, Giant, Newmen and Shimano’s own hubs. Apparently Shimano is going to be relaxing the licensing of its Micro Spline patent soon, but as of yet we’re still waiting for brands such as Hope and Stan’s No Tubes to be included in that list. Stay tuned on that one…

Shimano SLX M7100 12-Speed Chain

shimano slx m7100 12-speed 1x chain
There’s a new 50 buck chain for the SLX 12-speed drivetrain.

While not exactly as sexy as a rear mech or a huge 10-51T cassette, the new Shimano SLX 12-speed chain plays a vital role in the performance of the new drivetrain. Utilising an extended inner plate, the new chain is designed to mesh cleanly with the tooth profile on the 1x chainring for quieter and more secure chain retention. If it’s anything like XTR and XT, it’ll be darn smooth too.

As for the construction of the chain, it gets Shimano’s SIL-TEC coating on the roller link plates, and you also get the new quick-link master chain links inn the box with the chain. No more pins to push through to join the chain – woohoo!

Shimano SLX M7120 4-Piston Brakes

shimano slx m7120 4-piston four disc brakes
Shimano gives you the option of 2-piston or 4-piston callipers with its new SLX disc brakes.

To slow everything down, we’ve got a set of the new SLX M7120 disc brakes, which utilise 4-piston callipers. Labelled as the ‘Enduro’ option (the 2-piston brake is the lighter ‘Race’ version), the 4-piston calliper shares much in common with the latest XT and XTR 4-piston bangers. You get finned pads as stock, though small changes to the construction and surface treatment means the weight goes up a little while the price comes down.

Up at the lever end (which is the same whether you go for the 2-piston or 4-piston callipers), the new SLX master cylinder has exactly the same silhouette as the latest XT and XTR brake levers. There’s a mid-mount hinged clamp, which sees the body braced against the handlebar to improve overall stiffness, and therefore brake feel. You also get tool-free reach adjustment, and the Servo Wave mechanism for altering the power curve throughout the lever stroke. Rotors and adapters are sold separately.

shimano slx m7100 1x12 drivetrain groupset disc brakes 4-piston
The latest SLX groupset shares a tonne of features with 12-speed XTR, but comes in at a third of the cost!

We’ll be bolting the SLX components onto a test rig shortly in order to get plenty of summer saddle time on Shimano’s best-value 12-speed groupset. While we’re keen to see how it fares in the long run alongside the latest XT and XTR groupsets, we’re also eager to see how it compares directly with SRAM GX Eagle – a close competitor to Shimano SLX.

In the meantime, let us know if you’ve got any questions about the SLX groupset, and as always, be sure to tell us your thoughts in the comments below! If you’re after more 12-speed content in the meantime, you can read up on our latest thoughts on the XTR M9100 groupset, and the XT M8100 groupset here.

Mo’ Flow Please!

Enjoyed that article?

We did a SRAM GX vs Shimano SLX comparison here if you’re keen to hear more. Looking for a more budget friendly option, take a look at Shimano Deore.

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