The all-new Shimano XT M8100 group ushers in top-level performance borrowed from XTR, but brings the price down considerably and adds more options for trail and enduro bikes. The new SLX M7100 takes the price drop a step further while still offering wide range 12-speed cassettes and most of the same features. For the complete tech overview, read this post. Here are the basic specs and options for each part for both XT and SLX groups, plus a weight comparison between all three of Shimano’s current 12-speed mountain bike groups.
XT M8100 Parts & Specs
For XT, Shimano went with a Hollowtech II hollow forged arm with an updated shape. These are the same as the MT900 non-series cranks that were announced recently to start filling XTR orders until that group’s unique hollow-bonded arm design could catch up on production.
FC-M8100-1
– 172mm Q-Factor
– 52mm chain line works with 142 or 148 O.L.D.
– Prioritizes narrowest possible Q factor
FC-M8120-1
– 178mm Q-Factor
– 55mm chain line works with 148 O.L.D.
– Prioritizes frame and tire clearance
FC-M8130-1
– 181mm Q-Factor
– 56.5mm chain line works with 157 O.L.D.
Notes: The “-1” at the end of the model name indicates they’re shipping with 1x chainrings mounted to them. Single chainring options include 28, 30, 32, 34, 36T
FC-M8100-2 and FC-M8120-B2 Cranksets
– Double front chainring setup
– Swappable between single and double chainrings
– Chainring combination: 36-26T
– Chainline options: 48.8mm (FC-M8100-2, 172mm Q-Factor) and 51.8mm (FC-M8120-B2, 178mm Q-Factor)
CN-M8100 Chain
– New HYPERGLIDE+ shift technology
– Extended inner link plate
– Quick link for easy service.
CS-M8100-12 Wide Range – 10-51T
– Designed for single front chainring setup
– 510% gear ratio with smart gear steps to extend the range
– (10-12-14-16-18-21-24-28-33-39-45-51T)
CS-M8100-12 Rhythm Step Cassette – 10-45T
– Designed for double or single front chainring setup
– 450% gear ratio with ideal gear steps
– (10-12-14-16-18-21-24-28-32-36-40-45T)
The shifters get the best of XTR’s features, but with a larger thumb lever paddle.
SL-M8100-IR and SL-M8100-R – Right Shift Levers
– MULTI RELEASE allows the release of two gears at a time
– 2-WAY RELEASE with instantaneous push and pull movements
– Textured rubber pad on lever for grip
– 14mm slide range and 20-degree rotation for I-SPEC-EV (SL-M8100-IR)
SL-M8100-IL and SL-M8100-L – Left Shift Levers
– Front double shifting with single lever design
– 2-WAY RELEASE with instantaneous push and pull movements
– Textured rubber pad on lever for grip
– Natural finger position and intuitive shifting operation
The new XT rear derailleurs come in two variants…one for 1x setups only (left), and the other for 2x drivetrains with the smaller 10-45 cassette. In fact, you can only run the 10-45 cassette when paired with a double chainring up front as the 51-tooth cog is simply too much for either derailleur to handle when on the big ring…they’d have to make the cage too long to add enough chain, and that would create ground clearance issues. Both use 13-tooth pulleys.
RD-M8100-SGS Rear Derailleur for 1x Setup
– For single front chainring setup
– 51T max cog size
– Works with both 10-51 and 10-45-tooth cassettes
RD-M8120-SGS Rear Derailleur for 2x Setup
– Designed for double front chainring setup
– 45T max cog size
– Compatible with 2×12 speed or 1×12 with 10-45 cassette
Yep, you can still get a modern 2x mountain bike drivetrain with high end bits. While you probably won’t find any bikes spec’d like this in North America, it is available and will be on a few Euro brands…for Europe.
FD-M8100-D/E/M Front Derailleur
– SIDE SWING front derailleur
– D, E, and M-type mounts
– 10T total capacity
– 48.8mm and 51.8mm chain lines
The brakes get shared levers for both 2- and 4-piston calipers and all the adjustments you’d want and a refined Servo-Wave lever ratio for smoother braking power throughout the stroke.
BL-M8100 Brake Lever
– One XT brake lever for both 2-piston and 4-piston brake calipers
– Quick brake engagement with shorter free stroke
– Optimized lever axle position
– Refined ergonomics featuring a taller and flatter lever blade face
The brake calipers come with finned metal pads as stock, but non-finned and organic pads are available as options. Both use an inboard banjo housing routing for improved aesthetics. Model names are BR-M8100 (2-piston brake caliper) and BR-M8120 (4-piston brake caliper)
RT-MT800 – ICE-TECHNOLOGIES FREEZA Rotors
– Boosts heat dissipation bringing FREEZA technology to the XT group for the first time
– Reduces fade
– 140mm, 160mm, 180mm, and 203mm
Two sets of wheels are available, a lighter weight XC version that uses the new straight pull hubs with 24mm (internal) rims, and a burlier set with new wide-flanged, J-bend spokes and offset 30mm wide (internal) rim for a trail-worthy wheelset.
WH-M8100-TL – Lightweight tubeless wheels
– 28 straight pull spokes
– Inner rim with 24mm for use with tires up to 2.35-inches
– 27.5 and 29-inch diameter options
– E-THRU – 110 mm and 148 mm O.L.D.
WH-M8120-TL – Wider and stiffer wheels
– Zero Dish
– 28 J-bend spokes
– 30mm inner rim width for tires up to 2.6-inches
– 27.5 and 29-inch diameter options
– E-THRU – 110 mm and 148 mm O.L.D.
The hubs are also available separately to pair with your favorite rims.
HB-M8110/-B and FH-M8110/-B Hubs
– Lightweight aluminum FREEHUB body and driver plates
– O.L.D. – 100 mm (HB-M8110), 110 mm (HB-M8110-B)
– O.L.D. – 142 mm (FH-M8110), 148 mm (FH-M8110-B), 157mm (FH-M8130-B)
HB-M8110-BS and FH-M8110-BS – Straight pull DEORE XT Hubs
– 3-cross spoke pattern only
– O.L.D. – 110 mm (HB-M8110-BS)
– O.L.D. – 148 mm (FH-M8110-BS)
The PD-M8100 XC pedals get a slightly wider platform for better lateral stability under your shoe, plus an offset binding to help shed mud.
The PD-M8120 trail pedal’s platform is now a bit longer to give you more support, helping keep your feet comfortable on all-day rides.
The PD-M8140 platform pedals get a new concave design and 10 pins per side. They’re optional if you want to install them, and you’ll find sets of both 3.5mm and 5mm pins in the box. They also come in two sizes: Small (size 36-44EU shoes) and Large (43-48).
SLX M7100 Parts & Specs
The new SLX M7100 group brings most of the tech down to their most affordable trail-worthy group, including 12-speed cassettes, Dynashift+ and DCE+ chain management. There are a few sacrifices to costs, namely materials and finishes (and finishing), but functionally, all of the important stuff is here.
The SLX cranks also use HollowTech II construction and have a new “blue steel” finish that looks gray until the sunlight hits it. It, too, comes in single and double chainring variants using the same direct-mount pattern as XT and XTR. That means all chainrings from any group can be mixed and matched, and we’ll likely see aftermarket options pop up, too. SLX has a smaller variety of single chainrings, offering just 30, 32, and 34 tooth options.
FC-M7100-1
– 172mm Q-Factor
– 52mm chain line works with 142 or 148 O.L.D.
– Prioritizes narrowest possible Q factor
FC-M7120-1
– 178mm Q-Factor
– 55mm chain line works with 148 O.L.D.
– Prioritizes frame and tire clearance
FC-M7130-1
– 181mm Q-Factor
– 56.5mm chain line works with 157 O.L.D.
For the doubles, it’s the same basic deal, and the CN-M7100 chain simply gets different surface treatments but still uses the same extended DCE+ inner plates. You’ll have FC-M7100-2 and FC-M7120-B2 Cranksets with a 36/26 combo, and two chainline options:
– 48.8mm (FC-M7100-2 / 172mm Q-Factor)
– 51.8mm (FC-M7120-B2 / 178mm Q-Factor)
CS-M7100-12 – Wide Range Cassette – 10-51T
– Designed for single front chainring setup
– 510% gear range
– (10-12-14-16-18-21-24-28-33-39-45-51T)
CS-M7100-12 – Rhythm Step Cassette – 10-45T
– Designed for single and double front chainring setups
– 450% gear range with more ideal gear steps
– (10-12-14-16-18-21-24-28-32-36-40-45T)
The big difference with the shifters from XT is the lack of a rubber thumb pad, and they lose Multi-Release and Instant Release on the trigger. But, that trigger still works in both directions for releasing cable to go to a harder gear.
SL-M7100-IR and SL-M7100-R – Right Shift Levers
– Ergonomics focused on comfort and control
– 2-WAY RELEASE with instantaneous push and pull movements
SL-M7100-IL and SL-M7100-L – Left Shift Levers
– Front double shifting with single lever design
– 2-WAY RELEASE with instantaneous push and pull movements
The rear derailleurs come in both variants, one for 1x and one for 2x, and a front derailleur to match.
RD-M7100-SGS Rear Derailleur for 1x Setup
– For single front chainring setup
– 51T max cog size
– Works with both 10-51 and 10-45-tooth cassettes
RD-M7120-SGS Rear Derailleur for 2x Setup
– Designed for double front chainring setup
– 45T max cog size
– Compatible with 2×12 speed or 1×12 with10-45 cassette
FD-M7100-D/E/M Front Derailleur
– SIDE SWING front derailleur
– D, E, and M-type mounts
– 10T total capacity
– 48.8mm and 51.8mm chain lines
BL-M7100 Brake Lever
– One SLX brake lever for both 2-piston and 4-piston brake calipers
– Quick brake engagement with shorter free stroke
– Optimized lever axle position and refined ergonomics
The calipers are BR M7100 for 2-piston and BR M7120 for 4-piston variants. Shimano doesn’t disclose the actual piston sizes for any of these brakes, but our contact says those measurements haven’t changed from prior models.
With SLX, there are nearly silent hubs available, but no complete wheels.
HB-M7110/-B and FH-M7110/-B Hubs
– Lightweight aluminum FREEHUB body and driver plates
– O.L.D. – 100 mm (HB-M7110), 110 mm (HB-M7110-B)
– O.L.D. – 142 mm (FH-M7110), 148 mm (FH-M7110-B), 157 mm (FH-M7130-B)
SLX / XT / XTR Price & Weights Comparison
This table is a quick comparison of the key component weights for a sample complete group, comparing SLX to XT to XTR. For the complete weights for every size of every component, scroll to bottom…
| SLX | XT | XTR | ||||
| Component | Weight | Price | Weight | Price | Weight | Price |
| Rear Derailleur | 316g | $75 | 287g | $115 | 240g | $257 |
| Crankset | 631g | $105 | 620g | $155 | 534g | $420 |
| Chainring | ** | $33 | ** | $62 | ** | $133 |
| Bottom Bracket | 82g | $26 | 82g | $26 | 73g | $41 |
| Shifter (iSpec-EV) | 117g | $39 | 120g | $61 | 112g | $130 |
| Cassette | 534g | $100 | 470g | $160 | 367g | $390 |
| Chain | 252g | $32 | 620g | $155 | 534g | $420 |
| Brakeset | 311g | $175 | 301g | $210 | 279g | $326 |
| Rotor | 133g | $30 | 109g | $53 | 108g | $80 |
Notes:
- Cranksets are 175mm arms w/ narrowest Q-factor option, 32-tooth chainring
- Chainring weight is included in crankset weight
- Cassette weight is for 10-51
- Brakeset is weight and price per wheel w/ 4-piston calipers
- Rotor weight and price is per wheel for 180mm Centerlock
- Pedal weights (shown below) are for the pair
As listed, the complete groups with cranks, 32t ring, front and rear 4-piston brakes come in at:
- SLX = 2,820g / $820 (drivetrain only: 1,932g / $409.93)
- XT = 2,651g / $1,149 (drivetrain only: 1,831g / $623)
- XTR = 2,342g / $2,248 (drivetrain only: 1,568g / $1,436)
Wheel and Pedal weights
| M8120 XT Trail Wheels – 27.5″ | 1,891g | $420 |
| M8120 XT Trail Wheels – 29″ | 1,977g | $420 |
| M810 XT XC pedals | 342g | $120 |
| M8120 XT Trail pedals | 438g | $120 |
| M8140 XT flat pedals – small | 460g | $85 |
| M8140 XT flat pedals – large | 503g | $85 |
For comparison, the XTR pedals are 28g lighter for XC version, and 40g lighter for trail version, but cost $60 more…for the regular spindle.
Complete SLX, XT and XTR component weights list
Click to enlarge, and a huge thanks to Shimano for putting this chart together for us!
Ready to learn more about the groups? Read our complete tech overview here, and our first ride review here!
