New 12-speed groupsets aim to claw back ground from SRAM

New 12-speed groupsets aim to claw back ground from SRAM – we ride the new XT drivetrain and brakes.

Shimano Deore XT and SLX Need to know

  • Deore XT and SLX go 12-speed with 10-51 or 10-45t Hyperglide+ cassettes
  • Single-ring option with narrow-wide chainring or double chainset with front derailleur
  • New Deore XT shifter with Multi-Shift and two-way release
  • Two-bolt cranks with direct mount chainrings
  • New brake levers brace against the bar for extra stiffness
  • New XC and Enduro wheel sets available in 27.5in and 29in diameters

>>>Best groupsets of 2019

Scan through the spec sheets of any leading mountain bike brand these days and one thing will be abundantly clear: SRAM’s Eagle drivetrain has sunk its talons deeply into the high end market, to the point where Shimano has been left picking at scraps. Case in point; here at MBR, of the 45 full-suspension bikes that we’ve ridden this year, three quarters have been fitted with SRAM drivetrains.

With its new Deore XT and SLX groupsets however, the Japanese giant is on the attack, swords drawn and determined to recover lost ground.

And there’s more at stake than mere territory too. Faced with embarrassing delays to its flagship XTR group (announced last year) along with SRAM’s audacious move into wireless shifting, these workhorse groupsets are also about restoring reputation and pride. The importance of them cannot be underestimated.

Considering the weight bearing down on the shoulders of Deore XT and SLX, then, it’s almost an anti-climax to see the two finished products in the metal. There are no shimmering finishes or ingenious gadgets to hook the magpies. No carbon or titanium, and no in-your-face graphics. But then this is Shimano, and that’s not its style. Instead Deore XT and SLX take much of the architecture developed for new XTR and repackages it at two more affordable price points.

Two largest sprockets on XT cassette are alloy. SLX only gets alloy 51t sprocket.

So that means both now run 12-speed Hyperglide+ cassettes with wide-range 10-51 cassette options that literally one-up SRAM’s rival Eagle. This runs on Shimano’s own Microdrive freehub body – a unique, miniaturised spline design that is cleverly packaged but far from universally available across all wheel and hub brands.

Rear derailleurs are tucked away thanks to Shadow + design, and boast adjustable clutch friction 13T pulley wheel and bump stop to reduce noise and increase chain security

In a bid to cover all tastes and preferences, both Deore XT and SLX can be run in 2×12 configuration, which means there are front derailleurs, push/push Mono front shifter, double chainsets and a unique rear derailleur.

Hubs – still running loose ball bearings and a cup and cone system – are also available, although they will probably end up being as rare as 2X drivetrains when the new groupsets start appearing on MY20 bikes.

Rubber thumb pad is grippy and comfy but only appears on XT. SLX shifter uses different internals and lacks multi-shift functions

At the Doere XT level the shifter allows you truly flexible gear changes. You can select a harder gear with either your thumb (pushing forwards) or your forefinger (pulling back), and by adding a little extra speed and force, you can even dump two cogs at a time – useful for dropping in on a descent.

Easier gears can be engaged up to four at a time using the large rubber-covered thumb paddle, and new I-Spec EV mounts buddy up to the brake levers while allowing you to change the angle and position in relation to the grip.

New lever design brace against bar close to grip to increase stiffness. I-Spec EV mounts allow custom shifter positions

The brake levers themselves gain the new structure introduced on XTR last year that uses a thin clamp and an extra braces to reduce flex without taking up lots of valuable bar space. You can pair them up with either two or four-piston calipers and Ice-Tech Freeza rotors in 140, 160, 180 or 203mm sizes. These use an alloy core sandwiched by steel to radiate heat and are only available with a splined Centrelock fitting.

Classic twin-pinch bolt design updated with direct mount narrow-wide chainring. Crank arms do scuff up easily though and could do with clear plastic protection tape

Finally the crank retains Shimano’s excellent twin-bolt pinch design – one of the best systems on the market in our view – and hollow forged arm construction but gains a new direct mount chainring. Using a narrow-wide tooth profile for chain security, it’s available with 28, 30, 32, 34 and 36t options with 165, 170, 175 or 180mm arm lengths.

Always a shrewd cost-effective choice, SLX offers much of XT’s performance at a lower price

For the most part SLX uses cheaper materials and finishes to reduce costs, adding weight in places (most notably the cassette, but the whole group is 146g heavier) but also reducing function on a few key components.

For example, the SLX shifter lacks the multi-shift option found on Deore XT. There are fewer chainring sizes on offer and a less durable coating on the chain. But the overall look and feel is close enough to Deore XT that we can see it being an extremely popular choice when product managers come to spec their bikes next year. In fact, if we were to suggest the best bang for your buck, an SLX groupset paired with an upgraded Deore XT shifter would be tough to beat.

Dusty conditions in Spain for the press launch of XT and SLX

Riding impressions

It might not get the pulse racing to look at, but our first impressions of Shimano’s new XT groupset in the field were overwhelmingly positive (we didn’t get a chance to ride the SLX kit).

The highlight had to be the shifting, which was absolutely dependable, however ham-fisted we tried to be. Single down shifts on steep climbs were swift and accurate with minimal interruption to power or cadence.

Arriving at a punchy rise at the bottom of a descent and forcing through the full multi-shift and the drivetrain would crunch and ping in protest, but the chain would always end up four sprockets further up the block than it started. And in normal situations, shifts were completed with a low-key click or clack rather than an obvious clunk.

Two and four piston calipers are available and get finned brake pads to help cooling

On the way back down, the chain noticeably peels off the 51t sprocket, so there’s a delay between the shift and the chain dropping down fully, but that’s entirely to be expected as the wheel rotation is at its slowest. There’s a bit of twang as it drops off onto the next cog, but this seemed to depend on the frame we were riding – the stiffer Orbea Rallon enduro bike was much quieter in this respect than its XC racing cousin, the Oiz.

Being able to drop two gears at a time is a nice advantage too, and when rising out of the saddle it’s really natural to use your forefinger to flick the release paddle back and grab a taller gear.

Although there was no opportunity to put the heat on the brakes during our test rides, the bite point remained consistent – an area that has plagued Deore XT in the last few years. We’ll need longer with them before our confidence is fully restored, but it’s a good start.

There’s plenty of power and modulation too, with the new lever design feeling really solid thanks to its extra support against the handlebar. In fact our only complaint is that you need a lot of force to break the initial friction in the Servowave system, so the first millimetre of lever stroke feels sticky as a result.

In typical understated style them, from our early experience Shimano seems to have nailed it with the new Deore XT and SLX groupsets. Offering high performance, excellent quality and more options than most riders will ever want at a great price, these new groupsets represent an attractive package for both product managers and anyone looking to upgrade to 12-speed.

Weight and Price comparison chart

Shimano XT SRAM GX Eagle Shimano SLX SRAM NX Eagle
Rear Derailleur 284g










Shifter 120g










Cassette 470g










Chain 252g










Crankset 620g











Bottom Brackets

XT £32.99

SLX £32.99

Brakes (no rotors or adaptors)

XT four-piston £169.99

XT two-piston £129.99

SLX four-piston £149.99

SLX two-piston £99.99


XT rear £229.99

XT front £179.99