For many mountain bikers, the abbreviation "XTR" is synonymous with the best components they can bolt onto their bikes. The announcement of a completely new, even lighter XTR groupset therefore aroused high expectations: An unusual crankset with a hollow bottom bracket shaft, the freedom to choose between V-brakes and hydraulic disc brakes and, above all, a Dual Control-style brake shifter - fans and experts alike were excited. And let's get straight to the point: The update is only a partial success.
The workmanship of the aluminium parts is impressive; whether cranks, brakes or rear derailleur, the surfaces are of the highest quality and visually beautiful. The bottom bracket, in which a great deal of design intelligence has been invested, is also superb. The roller bearings have been relocated from the inside next to the bottom bracket shell: Without any modifications to the frame, this provides a significantly wider and therefore better support for the bearing. It also allows the installation of an enlarged shaft, which further increases stiffness. Praise is also due to the disc brakes fitted to the test bike, which do their job inconspicuously and powerfully.
However, the operation and function of the gears deserve criticism - although they follow a principle that should be familiar to racing cyclists: the gears are now changed using the brake levers. Compared to the road version, however, the Japanese have combined the shifting functions in one lever each. If you press the brake levers from above, you shift up on both sides of the handlebars, i.e. to the higher gear ratio. The front derailleur transports the chain to the large chainring and is therefore operated as usual; at the rear, however, the chain is transported to the smaller sprockets by pressing the brake lever. If you want to shift to a larger sprocket - i.e. an easier gear - you have to put your fingers under the lever and push upwards with the back of your fingers.
The change can be learnt, but in practice there are solid reasons against this so-called "inverse shifting". Firstly, when changing to larger sprockets, only one gear can be shifted at a time with each push of the lever. Secondly, the shifting process is slower, as only the spring force of the rear derailleur pushes the chain upwards. Where previously you could push in a lighter gear in steep sections with a little thumb force and a short release of the pedals, you are now at the mercy of the spring, which Shimano calls "Paradox". If dirt increases the friction in the system, the climb up many a steep ramp can end much sooner.
The operation of the levers is equally unpleasant. The fact that the index and middle fingers press the levers down makes sense. However, the lever travel is very long, so that the maximum of three gears that can be shifted at once can only be changed with long fingers or an additional twist of the wrist. Downshifting requires an almost unnatural movement. After some time on difficult terrain, the backs of your fingers start to ache. It hardly helps that Shimano has provided a (removable) second lever as a push button. This points almost vertically downwards and can only be reached with a long thumb or by letting go of the handlebars. Simultaneous braking and shifting to an easier gear is almost impossible if you still want to hold the handlebars firmly. Braking and shifting up would theoretically be feasible, but you hardly need to do this in practice.
XTR remains the first choice in terms of workmanship, durability and weight. However, it's not clear why the Japanese have ditched the impeccable Rapidfire Plus shifters in favour of a system that is significantly inferior in terms of ergonomics. What's more, the new system is only compatible with Shimano's own disc brakes. If Shimano gradually passes on the technology of the top groupset to the cheaper ensembles as usual, other manufacturers of disc brakes are in for a hard time. You can't help but get the impression that this is intentional. On the other hand, this may give SRAM's now well-functioning twist shifter systems a new chance to become more widespread. It could be exciting.
(Text: Dirk Zedler)
