Industry leader Shimano has taken the covers off its latest XTR family of flagship mountain bike groupsets. In a case of both evolution and revolution, the industry giant joins the 12-speed revolution as well as unveiling a host of new features sure to benefit cross country, enduro and marathon racers.
With two different mechanical only groupsets unveiled along with a host of new tech and features, read on for nine things to know about the all-new Shimano XTR M9100 series mountain bike groupsets.
- Related Reading: For a look at the new groupset in detail, head on over to CyclingTips for a comprehensive overview of XTR M9100.
1. Cross Country and Enduro groupsets
Designed specifically for racing, Shimano has released a number of versions of its flagship groupset, with one angled more towards XC (cross country) racers, the other Enduro racers.
Key differences between the two include all-new four-piston brake calipers and a stiffer crankset for enduro racers. All together, the new developments are claimed to shave 150 grams in weight off the older XTR M9000 XC groupset, whilst Enduro racers enjoy a 90-gram weight saving from a complete XTR M9020 Trail groupset.
2. Mechanical Only
Whilst the latest XTR group is loaded with new tech and features, there is one glaring omission, Di2. The electronic shifting technology pioneered by Shimano featured in the previous XTR range, however, there’s no official word on whether Di2 will feature on the new XTR at all.
As was the case with M9000 though, we hope to see wireless shifting added as an update within the groupset’s lifespan. However, at least for the moment, this new XTR is all about mechanical shifting.
3. Hyperglide+ Freehub
In order to accommodate the new smaller 10T cassette cog, Shimano has had to redesign it’s freehub technology to be more compact, all while allowing for that extra 12th cog. The end result is a new freehub design featuring “micro spline” technology dubbed Hyperglide+.
Shimano is keeping Hyperglide to itself, and only sharing the design with DT Swiss. In addition to Shimano’s new XTR hub range, it’s expected DT Swiss will produce adaptable freehubs to work with its hugely popular 3-Pawl and Star Ratchet systems.
4. Scylence Silent Hubs
Looking to the hubs and Shimano have a new technology inside called Scylence. This replaces the sprung pawls with a splined ratchet system to reduce drag whilst coasting and is claimed to create a virtually silent hub. The new mechanism offers 60 points of engagement, and the design uses all of them together for a seriously secure hold under power. Not only stronger, it which will be noticeably quicker on technical trails than the outgoing 36 points of engagement.
The rear hubs come in either 142 or 148mm (Boost specification) and are designed for a 12mm thru-axle while matching front hubs are also available in either 100 or 110 mm spacing with a 15mm thru-axle.
5. Gearing options
When considering what gearing options best suited the new developments made to the drivetrain, Shimano claim they wanted equal steps between gears to offer riders an optimal cadence regardless of the gear. The result is a 51T sprocket, which features equal gear steps of 6T in the last three sprockets. For riders not requiring such range, a 10-45T 12-speed cassette is also offered.
A third cassette option also exists which drops the 12th gear, but keeps the 10-45T cassette range. Think of this as the 12-speed drivetrain, but with one less cog. This special cassette works with its own XTR hub, which provides room to increase the spoke spacing in order to build a stronger and stiffer rear wheel. Otherwise, all of the components are the same as the 12-speed setup.
All three cassettes use a combination of metals in their construction which is said to allow the best balance of weight and durability. The largest sprockets use aluminium, the middle use titanium and the smallest use steel.
In addition to the new cassette design, a new 12-speed specific chain has also been added. Featuring extended links for increased chain security and hollow-pin construction for further weight savings, the new chains are also narrower to suit the new rear cassette design.
6. Lighter crank design
Joining the 12-speed shifting, Shimano has developed a new crankset design. The new cranksets now use direct mount chainrings, saving up to 80g in weight on the M9000 version as a result. These single-ring chainrings are available from 30T-38T. Enduro riders also have the M9120 crankset which is said to be a lighter stiffer, and a little wider to increase clearance on wide-set frames.
Riders who want a larger gear range than 1x can provide have the option of a 2x12-speed crankset that features 38-28T front chainrings. Using such a setup will require a specific rear derailleur, and of course a front shifter (more on this below) and front derailleur.
7. Updated brakes
The XTR braking systems score big updates, with the cross country and enduro brakes clearly defined. Both feature redesigned brake levers with a repositioned clamp band and lever body. The clamp moves towards the middle of the lever body which is said to create a stiffer brake, resulting in improved feeling and control.
For the M9100 cross country brakes, a simplified lever seeks to save weight. The contact point has been minimised, for more immediate braking control. At the caliper, a simpler hose entry saves weight, while the two piston setup uses the same brake pads as the previous generation.
The heavier-set M9120 Enduro brakes offer tooless lever reach adjustment at the lever, in addition to adjustable free stroke. While not new to this generation, the Enduro brakes also feature a power-increasing technology, known as ServoWave, which ramps up the amount of fluid pushed to the caliper as the lever is pulled. At the caliper, a wholly new four-piston design is said to increase power by 10%, while a larger pad is sure to aid in cooling and durability.
The rotor design has also been revamped, reducing weight and boosting heat dissipation. The 140 and 160mm rotors shed a claimed 5g and 10g respectively, whilst the 180 and 203mm rotors supposedly run 20°c cooler during sustained heavy braking efforts.
8. New I-Spec EV Shifters
Designed to increase shifting efficiency through improved handlebar ergonomics, Shimano has updated its shifter design for XTR M9100. The new I-Spec-EV designs are claimed to give 14 mm of lateral sliding range and 60 degrees of rotational positioning to allow riders to find their most ergonomic hand position on the shifters and brakes.
The new 12-speed rear shifter is said to have a lighter operational force which is claimed to bring a substantial decrease in shifting force and operation compared to XTR M9000.
For 2x12 riders, the front left-hand shifter also scores a simpler design, using just the one lever to shift up or shift down.
9. Other components
In addition to the standard groupset components, Shimano unveiled a range of other XTR components, including a dedicated dropper seatpost lever that’s compatible with many common [dropper seatpost] types on the market.
To aid in chain retention for enduro riding, a small range of top-type chain guides have been added, a first for Shimano.
The hugely popular XTR pedal range also sees some refinements. Looking at the M9100 cross country pedals, a -4mm spindle option will be available to make up the difference for the increased crank Q-factor. While both the cross country and enduro pedals are said to get refined aesthetics and improved mud shedding.
Confused by the shifty bits on your mountain bike? Check out our comprehensive guide to mountain bike groupsets for all you need to know.