Shimano is the undisputed market leader for bicycle gears. However, the success of the 1x12 drivetrains from the only serious competitor, Sram, is taking more and more market share from the market leader, especially in the high-end mountain bike segment. Although the Japanese countered Sram's advance with 1x options for all gear groups above SLX level and a new cassette with 11 to 46 teeth (420 per cent range), they were not really able to make up the lost ground. The electronic Di2 variants from Shimano are also hardly to be seen in the wild. But with the Shimano wants to relaunch the top XTR shifting group put the competition in its place.
12-speed: The new XTR is Shimano's first groupset with 12 sprockets
The new XTR drivetrain comes for the first time with a cassette with twelve sprockets and, with a gradation of 10 to 51 teeth and 510 per cent bandwidth, even outperforms Sram's Eagle drivetrains. To make room for the small 10-tooth sprocket, the decades-old gearing on the freehub is being abandoned for the first time in favour of a new micro-spline freehub, which is now set to become standard. Shimano justifies the 51 teeth of the largest sprocket with the fact that this gives an even jump of six teeth on the largest three sprockets (10-12-14-16-18-21-24-28-33-39-45-51 teeth).
2x fans can breathe a sigh of relief: XTR also available as 2x12 version
In contrast to the Americans, the front derailleur is not yet being buried in Japan. This is because the new XTR-M9100 - the XC and marathon version of the XTR - will also have a double version with 612 per cent gear range. Although the new crankset is still made of aluminium, as is typical for Shimano, it can be fitted with either single direct mount chainrings or a double chainring set. For fans of double gears, Shimano offers the 38/28 chainring combination as well as an extremely close-ratio cassette with twelve sprockets. The second twelve-speed sprocket has a gradation of 10 to 45 teeth. With a bandwidth of 612 per cent, this combination should appeal primarily to marathon riders and touring bikers. The left-hand gear lever is a "mono-shifter", i.e. there is only one lever. It works like a biro.
1x11 option as an extra
For purists, there is even a 1x11 version of the new Shimano XTR. The cassette then simply lacks the large 51 sprocket. This is to create space for more distance between the hub flanges and make the wheels more stable. The weight saving is at least 50 grams. For the time being, the new XTR is only available as a conventional mechanical drivetrain. However, there is already speculation about an electronic Di2 version in model year 2020. The new Shimano XTR M9100 is expected to be priced at the same level as the current XTR and will be available from September 2018.
XTR brakes: additional support for less torsion
The brake system has also been completely revised. In future, the brake lever clamp will be centred on the master piston. To minimise twisting when pulling the brake lever, the master piston also rests on the handlebars at the outermost corner. The stiffer brake lever is intended to provide a more direct braking feel. In addition to the brake calliper with two pistons for cross-country racers (BR-M9100), there will also be a version with four pistons and more power (BR-M9120). The braking power of this XTR four-piston brake should be on a par with the Shimano Saint or Zee. For enduro bikers, there will also be a crank with a wider Q-factor (168 instead of 162 mm).
In the past, Shimano has always promptly transferred XTR innovations to the more affordable XT groupset. If the Japanese remain true to their product cycles, they will have to show an XT drivetrain with twelve sprockets on the cassette next year.
Weights of the Shimano XTR M9100
If you only compare the drivetrain (chain, crank, cassette, shift lever), the new XTR M9100 saves 28 grams compared to the previous drivetrain with only eleven sprockets and a significantly lower gear range, according to the manufacturer. Compared to the Sram XX1 Eagle drivetrain, the new Shimano XTR is said to save only eight grams. The manufacturer's specifications for the individual components can be found in the table below. Detailed ride test of the new Shimano XTR M9100 will follow in BIKE 8/18. Incidentally, Sram already has another ace up its sleeve. As already shown in BIKE 5/18, the first prototypes of an electronic Eagle drivetrain are already circulating.
*All Shimano weights are manufacturer's specifications. Only the right-hand gear lever for the single option. Crank including 34 mm chainring. The weight specification refers to a pair of brake callipers and brake levers, without discs and screws for mounting.
First ride impression of the new Shimano XTR M9100
We had the opportunity to test the new XTR for a few metres to get a first impression of the new shifting group. The rubberised shift levers offer the thumb significantly more grip than the bare carbon levers of the predecessor. However, the operating forces when shifting are roughly on a par with the old XTR. Gear changes are precise and fast. If you turn the crank on the stand, it feels as if the chain is running a little rough on the cassette. However, the slightly rough feeling could also be due to the prototype status or the setting of the test bike. A definitive statement on this can only be made after further test rides. The second support for the brake lever on the handlebars actually makes it significantly stiffer. In purely visual terms, the lever hardly twists at all when braking. As usual with Shimano brakes, the pressure point on the handlebars is crisp, hard and well defined.
