The most versatile XTR groupset to date

Shimano XTR M9100 has gearing upped to SRAM-equalling 12 speed and includes 10-51t cassette. No sign of Di2 version yet though.

>>> Mountain bike groupsets: buyer’s guide

Shimano XTR M9100 need to know

  • Gearing upped to a SRAM Eagle-equalling 12 speed cassette.
  • Two gearing options include the massive 10-51 tooth range or closer ratio 10-45t.
  • Cassettes made from aluminium, steel and titanium.
  • Totally redesigned hub/freehub to accommodate the jump in sprockets.
  • New crankset uses direct mount chainrings to save further weight.
  • Rear derailleur loses swinglink upper pivot but increases jockey wheel size to 13 tooth.
  • Shifters feature new integrated I-SPEC EV mounts. Increasing positional adjustment to 14mm lateral and 60 degrees of rotational movement for optimised positioning.
  • Dedicated XTR dropper post lever compatible with all major cable-operate droppers.
  • Redesigned disc brake levers use the body as part of the clamp to create a stiffer brake.
  • Both two and four piston brake calliper options.
  • All parts of the brake system drop weight over their predecessors.
  • Front derailleurs and double chainring options still available.
  • 150 gram weight saving over M9000 (cross country), 90 gram saving in enduro guise.
  • Availability TBA.

Long standing as the flagship groupset in Shimano’s off-road range, the latest incarnation is being pushed beyond its cross country heritage. Shimano are claiming that the new XTR M9100 is the most versatile XTR groupset yet, aimed at cross country, enduro and marathon racers alike. And while we have seen several tweaks over the last couple of generations and an upping to 11 speed, this new version sees wholesale change, to the point where only the name remains the same.

The other big news is the absence of any news of a new electronic Di2 XTR M9100 groupset yet, has Shimano decided to pull the plug for off-road?

Shimano XTR M9100

Completely new hub design with Micro Spline freehub and Scylence ratchet internals.

Does 12 speed means a new freehub?

Front hubs from £54.99, rear hubs from £249.99

It goes without saying that the single biggest change with the new XTR M9100 groupset is the moving to a 12 speed cassette. In order to retain durability and sensible spacing between sprockets it was inevitable that Shimano needed to change their existing freehub design. Enter the new Micro Spline freehub. This uses a drastically changed spline arrangement from any existing Shimano freehub design in order to accommodate the changed cassette arrangement. Shimano has negated to supply measurements for the new freehub but expect it to be a touch longer as to require a specific hub to accommodate.

The new XTR M9100 hubs are also completely new. The rear now uses a new Scylence ratchet system rather than the traditional pawl arrangement to create an almost silent ride. Shimano state that this will help riders concentrate on the trail a little better. The new hubs will be available in 12 x 142mm or 12 x 148mm for the rear and both 15 x 100mm and 110mm front to meet the needs for both Boost and non-Boost frames.

Shimano XTR M9100

The whopping 10-51t cassette option. It uses a brand new Micro Spline freehub fitment.

Shimano XTR M9100 cassette options

12 speed £289.99, 11 speed £249.99

Three options will be available. The one that will have everyone talking is the Eagle beating 10-51 tooth whopper.

Mountain goats will rejoice in the bigger cog at the other end. Shimano has also kept equal jumps between the largest cogs to help maintain pedalling cadence (10-12-14-16-18-21-24-28-33-39-45-51T).

For the hard (wo)men or for less extreme courses, a closer ratio 10-45 cassette is on offer (10-12-14-16-18-21-24-28-32-36-40-45T).

Largest cogs are aluminium, middle made from titanium and the smallest from steel. Shimano are still using a pared down aluminium spider.

Somewhat interestingly, the third cassette option is actually an 11 speed cassette. Effectively it takes the 10-51 tooth cassette, removes the biggest sprocket and keeps the cog spacing the same as on the 12 speed version; but utilises the older 11 speed freehub and spline configuration. Shimano’s reasoning behind this is for riders to be able to create a lighter setup and use ‘stiffer wheels’ whilst still allowing for the use of a 12 speed chain and chainset. This wording does seem a little odd as it seems to imply that the new hub spacing and hub design isn’t as stiff as an 11 speed setup.

All three cassettes will use a tri-metal construction, with the smallest cogs made from steel, middle from titanium and largest constructed from aluminium. All cogs are mounted to a pared down aluminium spider. A standard cassette tool lock ring looks to still be employed to connect the cassette to the freehub.

Shimano XTR M9100

Direct mount chainrings and a slimmed down profile are features of the latest XTR crankset.

Shimano XTR M9100 crankset

Price: £309.99 (single ring) £439.99 (double).

Direct mount chainrings £99.99

M9100 sees Shimano turn to a direct mount fitment for the chainrings on the new crankset. Along with the slimmed down arms, this change allows Shimano to drop up to eighty grams off the weight. Plus it now offers riders more size options and if the fitment is the same, then this also allows access to more aftermarket chainring choices. Chainring options will be 30-38 tooth. For enduro riders there will also be the added piece of mind of the XTR chain device to prevent unwanted chain loss. Shimano will also offer a version with wider Q-factor to fit particular frame dimensions.

Shimano XTR M9100

The double option looks equally neat.

For riders still wanting to run a double, Shimano has created a direct mount double chainring. Currently we are unsure as to whether this is a single piece item or if the smaller chainring fits to the larger via standard chainring bolts.

Shimano XTR M9100

Angular and stripped down. The rear derailleur now features 13 tooth pulley wheels.

Shimano XTR M9100 rear derailleur, £189.99

looking altogether more angular and aggressive than XTR of old, the latest M9100 rear derailleur has a few interesting features. Firstly it loses the top swing link that has been used to mount the derailleur to the frame for the last few iterations. Instead Shimano has gone back to a solid top section, we expect this is to reduce weight and minimise failure points. Secondly, the pulley (jockey) wheels have been boosted to 13 tooth units to allow more chain wrap and better retention. It still retains the Shadow+ clutch mechanism to keep it bounce free on harsher terrain.

Three cage lengths will be available, long and short cage single ring options plus a long cage double compatible version.

Shimano XTR M9100

Alive and kicking. The front derailleur still features in Shimano’s XTR M9100 groupset.

Shimano XTR M9100 front derailleur, £89.99

Yep, the front derailleur is still alive and kicking according to Shimano. They still see a clear call for it and as such the new XTR M9100 will feature front derailleurs using their latest Side Swing design. All of the three most popular frame fitments will still be covered.

shimano XTR M9100

New shifter features a more customisable I-SPEC EV mounting system and the option to switch from 12 to 11 speed shifting.

Shimano XTR M9100 shifter, £94.99

Superficially the new shifters look similar to the existing M9000 but the new version has two distinct changes. Probably of most importance is the addition of a brand new I-SPEC direct mount option, called I-SPEC EV. This provides more customisation of the shifter position than ever before, with a claimed 14mm lateral movement and sixty degrees of rotation to position the shifter exactly where you want it. Don’t worry, Shimano still include a standard bar clamp version as well in the line up. The new shifter also has the ability to swap between 12 speed and 11 speed shifting, so giving a little backwards compatibility with existing groupsets and also to work with the new 11-speed cassette option.

Shimano XTR M9100

A single lever controls front shifting duties.

For users of front derailleurs the new front shifter is pretty unique. It uses a single ‘Mono’ lever to control shifting, simply push to shift up and click back to shift down.

Shimano XTR M9100 brakes, £219.99 (per brake)

Plenty of changes are noticeable with the XTR M9100 brakes. Still available in cross country and enduro versions, the biggest changes are found at the lever. The bar clamp has been repositioned in a more central location and the lever body has been brought in to be employed as part of the clamp. This Shimano says, is to increase lever stiffness to give a more direct contact feeling and improvement of control.

shimano XTR M9100

XTR M9100 brake levers see the bar clamp moved into the middle of the lever to create a stiffer clamp.

The 2-piston option comes with a lighter weight XC brake lever with the option to adjust the reach of the lever arm. The 4-piston brakeset also features a dedicated brake lever but with a tool-free reach adjust function, free stroke adjust function and Shimano’s Servo Wave technology to give rapid pad-to-rotor action. Both calipers are made from aluminum, use a high rigidity brake hose and provide faster brake engagement with a shorter free stroke.

Four piston ‘enduro’ brake features redesigned finned pads for more efficient cooling.

To match the redesigned caliper shape the brake pad shape also changes. Riders choosing the 4-piston caliper need the radiator finned pads, whilst the 2-piston calipers fit the pads without fins. The rotor design meanwhile uses a revamped ICE-TECHNOLOGIES FREEZA construction to either reduce weight or boost heat dissipation. The 140 and 160mm rotors shed 5 and 10g respectively, whilst the 180 and 203 mm rotors were 20°c cooler during testing with the 203 mm rotor also saving 30 g in weight.

Shimano XTR M9100

The new XTR dropper remote is discreet and features seamless integration with Shimano brakes.

Shimano XTR M9100 dropper remote, £44.99

A first for Shimano is a dedicated dropper seatpost lever. Coming with the new I-SPEC EV mount, it fits in-line with the new XTR brake levers. It promises to be compatible with all major cable operated seatposts and helps create a neat integrated cockpit.

Shimano XTR M9100 pedals,

£119.99 (XC), £124.99 (Trail)

Shimano XTR M9100

A little bit of polishing is all that looks to be different.

Shimano XTR M9100

More machining, this time for added grip.

Shimano will continue to offer both caged and non-caged SPD pedals for XTR M9100. As far as we can tell very little has changed barring a little cosmetic change to the finish on the smaller cross-country pedal and a little more machining for added grip on the trail/enduro version.