It’s been some time now since Shimano made its fans’ eyes glaze over at the 12 speed goodness from the XTR. For those who do not have an extra arm and leg to sell to purchase it, this news of the Deore XT and SLX groupset going 12 speed will be sweet music to their ears. Officially called the Deore XT M8100 and SLX M7100 series, the groupsets are now 12 speed and are both moulded from the same DNA as the much higher end XTR but available at more affordable prices.
The new Deore XT includes features such as Shimano’s groundbreaking 12-speed MICRO SPLINE cassette sprockets with either a 10-45T or 10-51T range, 1x12 or 2x12 Hollowtech II cranksets, powerful 2-piston or 4-piston brakes, fully adjustable ISPEC-EV shifters, 12-speed precision-shifting front and rear derailleurs, rapidly cooling Ice Technologies Freeza rotors and complete XC or Enduro wheelsets, all perfected for today’s mountain bikers.
With hollow crank arms to maximise weight reduction, pedalling the cranks just got way easier. To add on to that nice attribute, the crankset also comes with Dynamic Chain Engagement+ tooth, which is basically a narrow/wide teeth chainring. This is key to the improved chain retention, smoothness and quietness of the drivetrain. For secure and fast mounting of the chainring, the crank has a direct mount system to simplify how chainrings are changed. The Deore XT 1x12 crankset can be had in 28T, 30T, 32T, 34T and 36T chainring options, interchangeable with XTR and SLX rings, with crank length options of 165mm, 170mm, 175mm and 180mm. Deore XT cranksets are available for three chain lines:
52mm (FC-M8100-1) for Over Lock-Nut Dimensions (O.L.D.) of 142mm or 148mm, giving the narrowest 172mm Q-factor
55mm (FC-M8120-1) for an O.L.D. of 148mm for wider tyre and frame clearance (Q-factor 178mm)
56.5mm (FC-M8130-1) for an O.L.D. of 157mm and a wide Q-factor of 181mm
Crankset weights: FC-M8100-1: 620g, FC-M8120-1: 628g, FC-M8130-1: 636g (All 32T; 175mm, w/o BB)
The Deore XT 2X12 36-26T crankset offers the ultimate range when matched with the 10-45T cassette, maximizing the possibilities on all sorts of terrain whilst maintaining small gear steps for a consistent cadence.
Two 2x cranksets are available, both featuring a 2-bolt system for fixing the left side crank arm in place on the spindle. The FC-M8100-2 crankset has a 142mm O.L.D. for chain lines of 48.8mm and a Q-factor of 172mm. The FC-M8120-B2 crankset has a 148mm O.L.D. for chain lines of 51.8mm and a Q-factor of 178mm.
Weight for the FC-M8120-B2 (36-26T, 175mm, w/o BB) is 672g and for the FC-M8100-2 36-26T, 175mm, w/o BB) is 654g.
Deore XT 12-speed cassettes come with the Micro Spline fitting system and 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 for quick up and downshifts and an extremely quiet drivetrain. The cassettes have an aluminium spider to house ten steel sprockets and two aluminium sprockets for optimum durability and weight. The CS-M8100-12 10-51T cassette weighs 470g and the 10-45T option weighs 461g.
The new Deore XT 12-speed HG chain has been redesigned with 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 both up and down the cassette. The CN-M8100 chain (113 links + Quick Link) weighs 252g.
Coming in either single (RD-M8100-SGS) or double (RD-M8120-SGS) chainring variants, the Deore XT rear derailleur enables precise and quick shifting over a huge gear range. Both derailleurs feature Shimano Shadow RD+ positioning, bump stoppers and 13T pulley wheels to make rides quieter and more enjoyable. Rear derailleurs weights: RD-M8100-SGS: 284g, RD-M8120-SGS: 290g. The Deore XT front derailleur comes in one specification for both 48.8mm & 51.8mm chain lines but is available for D-type, E-type or M-type mountings. Front derailleur weights: FD-M8100-D: 135g, FD-M8100-E: 106g, FD-M8100-M: 114g.
With side adjustment and rotational adjustment options, the ISPEC-EV shifters (which bolt neatly to the brake lever) offer solutions for tailoring the ride feel. Rubber padding on the paddles and a two-way release enhances shifting even further. The right hand shifter (SL-M8100-IR) uses a multi-release feature to quickly dump cassette gears and, for riders using a 2x12 set-up, a MONO lever on the left (SL-M8100-IL) shifts the front derailleur both up and down with precision. Deore XT M8100 shifters are also available in a clamp band version. Shifter weights: SL-M8100-IR: 120g, SL-M8100-IL: 73g, SL-M8100-R: 117g, SL-M8100-L: 78g.
Deore XT brake calipers are available in an XC-specific 2-piston version or a Trail/Enduro 4-piston version. The 2-piston version shares the same design as the previous XT M8000 version, which means the previous G02A/3A/J02A/3A resin brake pads or G04S/J04C metal pads are compatible, whereas 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 (compatible also with D03S or D02S pads).
The Deore XT brake levers work with both the XC and Trail/Enduro calipers 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 sensation. The levers also feature a reach adjust dial and a free stroke adjustment screw for simple brake tune-ups on the trail.
XC style brake kits (BR-M8100-BL-M8100) with rotors (160 mm RT-MT800) and brake pads weigh 392g, while the Enduro style brake kits (BR-M8120-BL-M8100) weigh 410g including rotors and pads.
The redesigned Deore XT-level Ice Technologies Freeza rotors (RT-MT800) are meant to maximize cooling, resulting in consistent brake performance and longer lasting brake pads. A sandwiched aluminum core, fused in a durable steel outer layer, dissipates heat via the heat fins in the center. Sizes available are 140mm (88g), 160mm (109g), 180mm (132g) and 203mm (164g).
Unlike the XTR M9100 series, the Shimano Deore XT M8100 series offers complete 27.5 and 29” wheels for XC and Trail/Enduro riding. Shimano XC wheels offer a 24mm wide tubeless-ready, fully closed rim bed for tyres up to 2.35”. The 28 double-butted straight-pull spokes offer a perfect mix of stiffness and weight (WH-M8100-27.5: 1764g, WH-M8100-29: 1840g) for fast XC riding.
On the other hand, Deore XT Trail/Enduro-specific wheelsets offer a 30mm internal rim width made for tyres up to 2.6”. Rear hubs come with zero-dish (O.L.D. 148mm) and the aluminum rims take 28 J-bend spokes to keep these tubeless wheels strong yet light for aggressive riders and riding conditions (WH-M8120-27.5: 1846g, WH-M8120-29: 1932g).
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. Hub weights: HB-M8110: 142g, HB-M8110-B: 147g, HB-M8110-BS: 158g, FH-M8110: 305g, FH-M8110-B: 307g, FH-M8110-BS: 306g, FH-M8130-B: 310g.
In many ways, the SLX is similar to the Deore XT. The one area where it differs is its weight. Usually, the SLX components are heavier than the Deore XT, but the performances are comparable and similar at best. In the case of the new SLX and Deore XT the story is similar and we have narrowed it down to just the differences to make it easier to digest.
Main SLX differences to Deore XT: No free stroke adjust on brake lever, 1 aluminum cassette sprocket, less chainring options, no complete wheels, no multi release on right shifter, no textured padding on either shift levers, SIL-TEC coating on chain roller link plates, no Freeza technology on rotors. That translates to a 148g difference to the bigger sibling XT in like-for-like specification.
The SLX 1x12 comes with 30T, 32T and 34T chainring option whilst the Deore XT goes all the way down to 28T and up to 36T. Crankset weights: FC-M7100-1: 631g, FC-M7120-1: 638g, FC-M7130-1: 656g (all 32T; 175mm, w/o BB). The 2x12 options are the same. The FC-M7120-B2 (36-26T, 175mm, w/o BB) weighs 682g, while the FC-M7100-2 (36-26T, 175mm, w/o BB) weighs 674g.
The cassette T options are the same but the weights are different. The CS-M7100-12 10-51T cassette weighs 534g and the 10-45T option weighs 513g
Coming in either single (RD-M7100-SGS) or double (RD-M7120-SGS) chainring variants, the SLX rear derailleur enables precise and quick shifting over that huge 12-speed gear range. Both derailleurs feature Shimano Shadow RD+ positioning as well as bump stoppers and 13T pulley wheels to make rides quieter and more enjoyable. Rear derailleur weights: RD-M7100-SGS: 316g, RD-M7120-SGS: 322g. The SLX front derailleur comes in one specification for both 48.8mm & 51.8mm chain lines but is available for D-type, E-type or M-type mountings. Front derailleur weights: FD-M7100-D: 135g, FD-M7100-E: 166g, FD-M7100-M: 114g.
Just like the Deore XT, the ISPEC-EV shifters (which also bolt neatly to the brake lever) offer the same solutions for tailoring the ride feel. For riders using a 2x12 set-up, a MONO lever (SL-M7100-IL) on the left shifts the front derailleur both up and down with an extremely light and precise action. SLX M7100 shifters are also available in a clamp band version. Shifter weights: SL-M7100-IR: 121g, SL-M7100-IL: 73g.
The SLX-level Ice Technologies rotors (SM-RT70) are designed to cool rapidly thanks to a sandwiched aluminum core, fused in a durable steel outer layer, resulting in consistent brake performance and longer lasting brake pads. Sizes available are 140mm (121g), 160mm (133g), 180mm (159g) and 203mm (193g).
*At the same time, Shimano has also launched the new RX8 gravel shoes as well as Pro Tharsis endure components.