Shimano SLX Offers a More Affordable 12-speed Groupset

Shimano clearly has a solid, affordable, 12-speed mountain bike group at the table now with SLX.

We’ve all been wondering when Shimano would bring their own 12-speed drivetrain to the market. It happened a year ago with XTR, although not all of it was actually ready for the market. Today, Shimano announced a mid-tier 12-speed option that Singletracks tested in Bellingham, and the company is also launching an entry-level SLX option.

Shimano has always tried to trickle their technology down from premium components to more affordable components, and that’s what they’ve done with SLX.

Like the new Deore XT option, the 12-speed SLX M7100 comes with a Micro-Spline cassette in a 10-45T, or a 10-51T range, 1×12 or 1×12 cranksets, an SLX 12-speed chain, 2- or 4-piston brakes, adjustable I-Spec-EV shifters, front and rear derailleurs, and hubsets.


SLX 1×12 cranksets will feature Hollowtech II technology with an integrated axle and hollow crank arms. Chainrings come with a Dynamic Chain Engagement+ tooth profile, which is a narrow/wide tooth pattern. This aids chain retention and the quietness of the drivetrain.

The crank is equipped with a direct-mount system for easy chainring mounting and cranksets come with a 30t, 32t, or 34t chainring option, interchangeable with XTR and XT rings. Crank lengths are available in 156mm, 170mm, or 175mm.

The cranksets are available in three chain lines:

    • 52mm (FC-M7100-1) for Over Lock-Nut Dimensions (O.L.D.) of 142mm or 148mm to give the narrowest 172mm Q-factor (Claimed weight: 631g)
    • 55mm (FC-M7120-1) for an O.L.D. of 148mm for wider tire and frame clearance. Q-factor: 178mm. (Claimed weight: 638g)
    • 56.5mm (FC-M7130-1) for an O.L.D. of 157mm and a Q-factor of 181mm (Claimed weight: 656g)
    • (All claimed weights are with a 32t ring, 175mm crank length and without BB)

The 2×12 crankset offers a great amount of range with the 10-45t cassette. The cranksets are available to match Boost and non-Boost Q-factors and chainlines. They weigh 674g-682g.

Cassette and chain

The SLX 12-speed cassettes with Micro-Spline are available in a 10-45t or a 10-51t sizes. Both feature Hyperglide+ for quick shifting. The cassettes have an aluminum spider to house eleven steel sprockets and one aluminum sprocket for a balance of durability and weight. Claimed weights are 534g for the 10-51T and 513g for the 10-45T option.

The SLX HG chain has been redesigned with an extended inner plate to improve engagement and retention. Claimed weight is 252g.


Derailleurs come in either a single (RD-M7100-SGS) or double (RD-M7120-SGS) options. All derailleurs feature Shimano Shadow RD+ to make shifting more quiet. Claimed weights are from 316g to 322g.

The front derailleur comes in one spec that fits both 48.8mm and 51.8mm chain lines, but are available for D-type, E-typse, or M-type mounts. They weigh between 114g and 166g.


Shifters offer side and rotational adjustment options on the I-spec-EV shifters and bolt to the brake lever for a neat, personalized feel. The left, front shifter weighs 73g and the rear shifter weighs 121g.


SLX calipers are available in an XC-ready 2-piston version, or a trail/enduro-ready 4-piston version. The 2-piston version is the same design as the previous version, meaning that the previous SLX resin or metal pads are compatible. The 4-piston version is brand new, inspired by the new XTR M9100 design and uses D03S (resin) or D02S (metal) pads. They’re also compatible with N03A and N04C finned pads.

The SLX levers work with both of the calipers and feature the Shimano Servo wave system for better engagement, improved power, and a shorter free stroke. The levers feature a reach adjust dial for easy personalization. XC-style kits with 160mm rotors and pads weigh 425g. The enduro-style kits weigh 444g including rotors and pads.

The SLX Ice-Tech rotors (SM-RT70) are designed to cool rapidly with a sandwiched aluminum core, surrounded by a steel outer layer. They’re available in 140mm, 160mm, 180mm, and 203mm diameters.


SLX hubs are available in 100mm and 142mm, 110mm and 148mm, or 157mm. The freehub features a Micro-Spline cassette body.

Weights, summarized

  • M7100 Cranksets, 32t ring, 175mm, w/o BB: 631g
  • CS-M7100-12, 10-51t cassette: 534g
  • CN-M7100 chain: 252g
  • RD–M7100-SGS derailleur: 316g
  • SL-M7100-IR shifter: 117g
  • BB-MT800 bottom bracket: 82g
  • Disc brake set, BL-M7100/BR7120: 311g
  • SM-RT70-S rotors: 133g per rotor
  • SLX group with 1×12, 32t ring, front and rear 4-piston brakes w/ 160mm rotors: 2820g
  • SLX drivetrain only: 1932g


  • M7100 Cranksets, 32t ring, 175mm, w/o BB: $104.99
  • CS-M7100-12, 10-51t cassette: $99.99
  • CN-M7100 chain: $31.99
  • RD–M7100-SGS derailleur: $74.99
  • SL-M7100-IR shifter: $38.99
  • BB-MT800 bottom bracket: $25.99
  • Disc brake set, BL-M7100/BR7120: $174.99
  • SM-RT70-S rotors: $29.99
  • SLX group with 1×12, 32t ring, front and rear 4-piston brakes w/ 160mm rotors: $819.89
  • SLX drivetrain only: $409.93

Differences between SLX and XT

Like most differences between entry-level components and mid-tier or premium, the SLX weighs more, is a little less crisp or fast, and isn’t quite as aesthetic. Other differences include the absence of a free-stroke adjustment on the SLX brake lever. There are also fewer chainring options, no complete wheelsets, and no multi-release on the right shifter or textured padding on the shift levers.

Compared to SRAM

Compared to a drivetrain option from SRAM, the 12-speed Shimano SLX ($410) sits above NX Eagle ($375) in price and below GX Eagle ($500).

The SLX drivetrain weight (1932g) is slightly lighter than the NX Eagle (2050g), but heavier than the GX Eagle (1747g).

So, of course this would position the SLX as a more attractive option than NX Eagle since it is slightly lighter at only about $35 more. Then again, maybe four ounces isn’t worth the extra cost to you. The caveat is that the cassette options from Shimano offer a little bit more range than the SRAM NX cassettes.


Conversation and internet chatter has rambled on for the past few years as to when Shimano would catch up to SRAM with 12-speed drivetrains. They released their first and most expensive XTR option near the same time last year when SRAM trickled down its last bit of technology to NX Eagle. Now it seems like the energy has shifted again, this time toward electronic drivetrains following the release of SRAM AXS.

Looking at the numbers, Shimano clearly has a solid, affordable system at the table now with SLX.

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