Despite receiving significant updates in recent years, Shimano has revealed fresh overhauls of two of its most popular groupsets, with Deore XT and SLX both upgrading to 12-speed technology.
Available from mid-June, the Deore XT M8100 series will feature 12-speed ‘micro spline’ sprockets, with the choice of a 10-45T or a vast 10-51T range. These can be paired with a 1X12 or 2X Hollowtech cranksets and adjustable ISPEC-EV shifters.
Deore XT sits at the top end of Shimano’s MTB groupset offering, with the Japanese maker’s premium XTR the only higher-level component set.
The answer was in making a set of components in the right grade and specification to match the competitive ambitions of mountain bikers
XTR received a 12-speed upgrade in 2018 and many of the technologies developed for that pro-level gruppo have now found their way into XT.
While SLX is lower in the pecking order, its attractive price and balance of quality has ensured its position as a popular mainstay on the trail and deserving of some spit and polish.
It’s M7100 update includes the same micro spline cassette technology as XT, again featuring the 10-45T and 10-51T set-ups with 1×12 or 2×12 options, just like its bigger brother.
It’s also got a dedicated 12-speed chain, just for SLX M7100, underlining the commitment to development Shimano has for its value-centred options.
Commenting at the launch, Shimano Europe MTB product coordinator, Henry Bosch, said: “While speed, focus, and control was the mantra we lived by during the XTR development, we needed to widen that for Deore XT and SLX.
“We thought a lot about how and why people ride mountain bikes. For us the answer was in making a set of components in the right grade and specification to match the competitive ambitions, the adventurous riding styles, and the performance quality of mountain bikers across the globe – above all, making sure riders receive durable performance to have as much fun as possible.”
Aside from the features mentioned above, the M8100 highlights include 2-piston or 4-piston brakes with Ice Technologies Freeza rotors to maximise cooling and braking performance on downhill sections.
Complete XC or Enduro wheelsets have also been developed for M8100, with both 27.5 and 29” options.
The XC wheels offer a 24mm wide, tubeless ready, fully closed rim bed for tyres up to 2.35”. The Enduro-specific wheelsets, meanwhile, offer a 30mm internal rim width for tyres up to 2.6”. Rear hubs come with zero-dish and aluminium rims featuring 28 J-bend spokes to keep your tubeless wheels strong yet light.
The Deore XT 1X12 crankset features Hollowtech II crank arms with an integrated bottom bracket axle and hollow crank arm. Chainrings come with a Dynamic Chain Engagement+ tooth profile, with narrow-wide teeth for improved chain retention, smoothness and quietness. A direct mount system on the crank simplifies chainring changes. The crankset comes with 28T, 30T, 32T, 34T and 36T chainring options, interchangeable with XTR and SLX rings. The crank lengths available are 165mm, 170mm, 175mm and 180mm (increasing in weight respectively from 620g to 636g).
For the 2X cranksets, Shimano says its 36-26T crankset is best matched with the 10-45T cassette, maximizing the range while maintaining small gear steps.
The XT 12-speed cassettes are available in a 10-45T option for small gear steps or a 10-51T option for maximum range. Both cassettes also feature Hyperglide+, allowing quick up and downshifts with quiet operation. The cassettes have an aluminum spider, housing ten steel sprockets and two aluminum sprockets. The 10-51T cassette weighs 470g and the 10-45T option weighs 461g.
The new DEORE XT 12-speed HG chain offers an extended inner plate to improve chain engagement and retention and comes with chromized roller link plates for enhanced durability and smoother and faster shifting. With 113 links + quick Link, it weighs in at 252g.
Two derailleurs are available for XT M8100, one for the single chainring and one for double. Both feature Shimano Shadow RD+ positioning, bump stoppers, and smooth 13T pulley wheels. The single derailleur weighs 284g and the double 290g.
The front derailleur comes in one specification but is available for D-type (135g), E-type (106g) or M-type (114g) mountings.
The ISPEC-EV shifters offer options for riding feel. They feature rubber padding on the paddles and a two-way release. The righthand shifter for 1X (120g) uses multi-release to quickly dump cassette gears while 2×12 riders get a MONO lever on the left (78g) for the front derailleur.
The 2-piston version shares the design of the XT M8000 version, so your G02A/3A/J02A/3A resin brake pads or G04S/J04C metal pads remain compatible. The 4-piston version is a completely new construction drawn from the XTR M9100 design, sharing the same N03A (resin) or N04C (metal) finned pads.
The XT brake levers work with both the XC and Trail/Enduro callipers and come equipped with Shimano’s ‘Servo’ wave system for quicker engagement, improved power, and a shorter free stroke.
The brake levers are now angled in two positions against the handlebar for a stiffer brake feel and include reach and free stroke adjustment.
XC style brake kits and brake pads weigh 392g and Enduro style brake kits weigh 410g including rotors and pads.
The XT-level Freeza rotors include a sandwiched aluminium core, fused in a durable steel outer layer, available in 140mm (88g), 160mm (109g), 180mm (132g), and 203mm (164g) variants.
Both the XC and Trail/Enduro rear wheels feature E-THRU axles (15mm front, 12mm rear), 148mm O.L.D. widths and come with Shimano’s micro spline cassette interface on the rear hubs.
Individual Deore XT front hubs and freehubs are also available in widths of 100mm and 142mm, 110mm and 148mm, and 157mm.
Many of the updates to XT have found their way in one form or another to SLX, giving those new to mountain biking, or simply on a budget, access to top-line tech.
Again, fully adjustable ISPEC-EV shifters feature, along with 2-piston or 4-piston brakes.
Shimano have worked hard to ensure there is little separation between SLX and XT in terms of function, with the extra 148g in comparable parts being the only consistent difference.
Just like XT, the SLX 1×12 crankset features Hollowtech II design with integrated bottom bracket axle and hollow crank arms. The arrow/wide teeth also return with 30T, 32T, and 34T chainring options that are interchangeable with XTR and XT rings – options include 165 mm, 170 mm and 175 mm.
The micro spine fitting and 10-45T or 10-51T options return for SLX as does Hyperglide+. The cassettes have an aluminum spider with eleven steel sprockets and one aluminium sprocket. The 10-51T cassette weighs 534g and the 10-45T option weighs 513g making them heavier than their XT counterparts but not by much.
The same inner plate of XT has made it to SLX with SIL-TEC roller link plates for smoother running. The 113 link chain weighs 252g – the same as XT.
The single or double SLX variants again feature Shimano Shadow RD+, bump stoppers, and 13T pulley wheels but weigh around 20-30g more than the XT versions, as does the SLX front derailleur.
Again, the same side adjustment and rotational adjustment in the ISPEC-EV format, although there is no multi release on the SLX 1X or textured padding on paddles. Weights are the same as XT.
Just like XT, the 2-piston SLX brakes share the design as the previous version, meaning owners of SLX-level G02S/J02A resin brake pads or G04S/J04C metal pads brake pads can keep them. The 4-piston version, built from the XTR M9100 blueprint, uses the same D03S (resin) or D02S (metal) brake pads.
The levers work with both the XC and Trail/Enduro calipers and feature the ‘Servo’ wave system for quicker engagement, improved power, and shorter stroke – there’s no free stroke adjust, however. They’re also angled and feature the reach adjust of the XT version. The rotors don’t share the Feeza technology and weigh around 30g more than XT’s.
Individual SLX front hubs and rear freehubs are available in widths of 100mm and 142mm, 110mm and 148mm, or 157mm.