Shimano XT M8100 12-speed groupset, all you need to know.

New Shimano Deore XT groupset brings 12-speed features to mountain bikers

Original MTB performance groupset and best pound-for-pound groupset go 12-speed

Building on the experiences of the world’s best mountain bike racers, Shimano has brought its race-winning technology to competitive and enthusiastic mountain bike riders.

The new DEORE XT M8100 series, the latest iteration of the original MTB groupset, continues its legacy with high-performance features for today’s demanding and adventurous mountain bikers.

DEORE XT - durability and performance for today’s mountain bikers

The new DEORE XT M8100 series 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.

Cranksets

The new 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, which, with its narrow/wide teeth, 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 chain rings are changed. The crankset comes with 28T, 30T, 32T, 34T and 36T chainring options, interchangeable with XTR and SLX rings, has 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 HOLLOWTECH II 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.

Cassette

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 aluminum spider to house ten steel sprockets and two aluminum sprockets for optimum durability and weight. The CS-M8100-12 10-51T cassette weighs 470g and the 10-45T option weighs 461g.

Chain

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.

Derailleurs

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.

Shifters

With side adjustment and rotational adjustment options the ISPEC-EV shifters, which bolt neatly to the brake lever, offer solutions for tailoring the riding 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.

Brakes

DEORE XT brakes 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 new 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 and Enduro style brake kits (BR-M8120-BL-M8100) weigh 410g including rotors and pads.

Rotors

The redesigned DEORE XT-level ICE TECHNOLOGIES FREEZA rotors (RT-MT800) are designed 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).

Wheels

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.

Summing up a huge range of options it’s clear that the new DEORE XT M8100 series provides high-performance features for today’s demanding and adventurous mountain bikers, whereas the SLX M7100 series, sharing the same DNA, draws on this inspiration to bring quality performance to those discovering the fun of mountain biking.

Henry Bosch, Shimano Europe MTB product coordinator: “Whilst 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 that riders receive durable performance to have as much fun as possible.”