Everyone was expecting Shimano to introduce the new XT M8100 12-speed drivetrain. But we were surprised to see the Japanese giant also release a new 12 speed Shimano SLX M7100. Both groupsets rely on the proven features of their high-end XTR drivetrain. Not only do we have all the details on the new drivetrains for you, but we’ve already taken them for a ride.
Surely a lot of Shimano fans have been waiting for this: Finally, the icon among drivetrains, the Shimano XT, is available in a 12-speed version. It was an overdue update for the Japanese brand, after all, SRAM were clearly dominating the market with their 12-speed drivetrains in recent years. Not even Shimano’s flagship XTR groupset has really taken off due to delivery problems. All this is set to change with the introduction of the new XT and SLX 12-speed groupsets.
Shimano XT and SLX in detail
The new Shimano XT M8100 and also SLX M7100 drivetrains are available both as a 1x option with a large 10-51T cassette and a 2x version with a 10-45T cassette. Thanks to the improved adjustability of the new, more ergonomic and easy actuation of the I-SPEC EV shifters, both groupsets can be fully adapted to the riders’ preferences. A lot of the technology of the top-end XTR groupset can now also be found on the XT and SLX. Both feature the HYPERGLIDE+ system. What sounds like a Durex advertisement ensures that the chain glides from one cog in the cassette to the next with almost no interruption in power transmission.
Both the Shimano XT and the SLX groupsets feature new brakes on which we have written a separate article summarising all the details.
The Shimano XT and SLX 12-speed derailleur
The new Shimano XT and SLX derailleurs rely on 13T pulleys. Both groupsets have a specific 1x and a shorter 2x model. Of course, all of the different models include the integrated clutch. The main difference between the XT and the SLX models is in the surface treatment and the fact that the pulleys of the XT derailleur come with ball-bearings. Regarding weight, the 1x versions of the XT and SLX derailleurs have a difference of 32g, in favour of the XT.
The Shimano XT and SLX cassette
Both cassettes come with a gear range of either 10-51T (1x) or 10-45T (2x). They interface with the freehub body via MICRO SPLINE and feature the HYPERGLIDE+ technology introduced on the latest XTR groupset, for fast and quiet shifting. The XT cassettes consist of ten steel sprockets and two aluminium sprockets attached to an aluminium spider. The structure of the SLX is identical, but one of the aluminium sprockets is steel, weighing in at a total weight of 534 g (10-51T), 64 g heavier than the comparable XT model (470 g).
The Shimano XT and SLX cranks
There are quite a few similarities between the XT and SLX cranks. Both feature HOLLOWTECH II crank arms, are available in 1x and 2x versions and have the narrow-wide tooth design for optimal chain retention. While the 1x XT crank is available with direct-mount chainrings from 28-36T, you’ll have to do without the smallest and biggest chainring options on the SLX – although it is compatible with the XT and XTR chainrings. The XT offers more options with regards to crank length as well, available in 165, 170 and 175 mm as well as a 180 mm version. The SLX range doesn’t include the longest option. Of course, both are available for different axle standards. In terms of weight, the two are separated only by about 11g (620 g XT and 631 g SLX, each with a 32T chainring, and without the bottom bracket).
The Shimano XT and SLX shifter
The key update of the new Shimano SLX and XT shifters is I-SPEC EV. The new system allows riders to optimally adjust the position of the various levers to suit the ergonomics of their own hands. The main difference between the two is hidden inside the shifters. While the XT shifter offers the proven multi-shift function to shift down two gears at once, the SLX shifter will only do one gear at a time. The XT shifter also features rubberised thumb pads, whereas Shimano have given the SLX shifter a bit of texture instead. Shimano offer a single left-hand lever for their 2x drivetrains. In weight, the differences are marginal: the SLX and XT shifters are separated by only 1g (120g XT, 121g SLX).
The Shimano XT and SLX chain
The 12-speed SLX and XT chains differ in their surface treatment. The insides of the chain links have been revised on both chains to improve chain management on the sprockets. The weight of both chains is identical at 252 g. They come with a quick-link as standard.
First ride review: Shimano XT and SLX 12-speed
We’ve already had the opportunity to test both the new Shimano XT and the SLX 12-speed drivetrains. We took the XT drivetrain to a cross-country track in Girona, and we put the SLX drivetrain to the test on an enduro ride. They performed flawlessly during testing and we were particularly impressed with the fast and precise shifting on both of them. Even when shifting two gears at once with all our weight on the pedals, the drivetrains did as they were told without problems, no creaking or any delays. The chain glides from one cog to the next, very quietly yet defined. The feel of the XT shifter feels slightly crisper and more precise. Shimano’s rather long lever action has remained unchanged compared to SRAM. The possibility of dropping two gears at once with the XT shifter is an ingenious thing, which is why we personally would always invest a bit more and go for the XT model.
Thanks to the wide gear range, even long and steep climbs are no problem for either drivetrain. We deliberately removed the chain guide halfway into our enduro ride and we still didn’t manage to drop the chain even once. The clutch works very effectively and both drivetrains are nice and quiet. We’re not yet able to assess the durability and reliability of the new 12-speed drivetrains – but we are very much looking forward to further and longer testing.
Price and availability of the new Shimano SLX and XT
After a long wait for the XTR, we are all the more curious about when the new XT and SLX will be available in stores. According to Shimano, everything is going according to plan and delivery will start on the 14th of June this year. The prices aren’t available in Euros yet. Since Shimano don’t have recommended retail prices, we’ll have to wait for the individual distributors to calculate their prices.
The new Shimano SLX and XT are eMTB ready
According to Shimano, both the new SLX and XT drivetrains are easily suitable for use on eMTBs. It does not need a special lever or anything else. Since the SLX cassette has another steel sprocket, it should be here longer lasting.
Our first conclusion on the new Shimano XT and SLX 12-speed drivetrains
With the new Shimano SLX and XT 12-speed drivetrains, the Japanese brand is back in the races. The wide gear range and the fast and super smooth shifting convinced us. Compared to the SLX, the new XT feels more crisp and of slightly more high-end quality. However, the price will show if it’s really worth the upgrade. On a purely functional basis, there is little to complain about on the entry-level groupset. What we’re excited about now is not only how the drivetrains will fare in the long run, but also how soon we’ll see more hub manufacturers offering the MICRO SPLINE free hub.
For more information head to bike.shimano.com
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