A fair dinkum intro to XTR M9000 and Di2 electronic shifting - Part 1

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smith-XTR-2188News of Shimano’s latest XTR offerings has been circulating for some time now, but actual product has been scarce and near impossible to experience in the flesh. Last week we had our first introduction to the latest groupsets here in Wellington (at the local Shimano Service Course) and then, over Labour weekend, I travelled to Western Australia with other Australasian media to get more closely acquainted with the new XTR 9000 group-set and Di2 electronic shifting. Most importantly, I finally got to put in some riding time on these products and develop some initial thoughts.Here they are.

XTR M9000 Groupset highlights While much of the fanfare from Shimano this year will be focused on the introduction of Di2 electronic shifting (more on this in the next instalment), let’s start by having a look at some of the key changes and highlights of the revised mechanical groupset; XTR M9000. The biggest and most obvious change is the move to an 11 speed system. Unlike SRAM, who are focusing on 11 speed as a solution to running a single front chainring, Shimano are sticking to their guns and pushing multiple chainring setups. Therefore, although the rear cassette has eleven gears, and offers a pretty broad range (11–40 teeth), it’s not as broad as the SRAM solution. Instead Shimano believe that their approach to 11 speed offers a better progression through the gears, with smaller steps, on average, allowing riders to more easily stay within their preferred cadence as they work their way through the rear cassette.

smith-XTR-2165 11 speed cassette The rear cassette itself looks innocent enough, but has a bill of materials that would make the most dandy of engineers blush. A mix of steel, aluminium, and titanium cogs are brought together on a carbon spider. The good news for many of us is that Shimano have managed to squeeze their 11 speed cassettes on to a 10 speed freehub. So, if you’re currently running 10 speed and want to upgrade to 11 speed you can do so without having to replace your freehub body and/or wheelset.

smith-XTR-2168 Cranks and chainrings Up front there are multiple options for cranks and chainrings. There are two crank types: the ‘Race’, and the ‘Trail’. The key difference between the two is that the Race is a hollow bonded construction, while the Trail is a cold forged construction. This makes the Race crank the lighter of the two. The other important difference is that the Race crank can be run in a double or single chainring setup, while the Trail crank can be run as triple, double, or single. The cranks themselves can be swapped from configuration to configuration by replacing the spider arm. The Race crank also has a narrow Q-factor of 158mm, while the Trail is a standard 168mm.

Each crankset has one ‘Hollowglide’ chainring (the larger on the double ring setups, and the middle on the triple) that features a carbon/aluminium construction with titanium teeth. Shimano claim that these are the “most advanced mountain bike chainrings ever produced” and that the construction improves stiffness and reduces weight. Remaining chainrings are, comparatively, less exotic and made from aluminium. While all Shimano chainrings are designed for efficient shifting, there have been some slight changes made to the tooth profile to provide additional chain retention.

smith-XTR-2157 Rear derailleur As well as being redesigned specifically to work with 11 speed, the rear derailleur has had a few other changes worth noting. Firstly, the clutch mechanism is now externally adjustable, so if you choose to you can run less (or more) resistance. This allows you to make your own call on how you’d like to manage the compromise between chain retention and ease of shifting. You might also notice from the image that the on/off position for the clutch has been reversed. This was done to avoid frame clash issues that a few people had experienced with the previous generation. Finally, also worth mentioning is that the rear derailleur has been further reduced in profile to help minimise the likelihood of it being damaged.

smith-XTR-2160 Front derailleur Front derailleurs have typically been relegated to the back of the pack in recent years in regards to significant improvements and changes. However with the introduction of the M9000 groupset, Shimano have made a notable and important introduction to the lineup. The ‘Side-swing’ front derailleur is designed to improve tyre clearance and thus better accommodate the bigger wheels and increased rear suspension travel that is now the norm on modern trail bikes. In addition to 15mm of extra clearance, the side swing front derailleur uses has a cable routing that enters from the front of the bike; this is said to simplify the path of the cable and improve ease of shifting.

smith-XTR-2175 Shifters There have been a few changes in the shifter department for M9000. These changes include a slightly longer lever and “slicker” cable construction to make shifting easier (20% easier apparently). Plus the shape of the carbon shifter levers (specifically the release lever) has been changed to make them more user friendly and delightful to the touch. Finally there is the new i-spec II mounting system that provides a little more lateral and rotational adjustment so you can fine tune shifter position a little more.

smith-XTR-2179 Brakes Shimano brakes, in particular the XTRs, have gone from strength to strength in recent years and are well regarded for their power, feel at the levers, and ability to disperse heat buildup. But they haven’t been without issues and one of the key changes in the new brakes is a move to a phenolic resin piston (as opposed to a ceramic one) which is said to have better heat resistance, and to be less prone to occasional weeping (fluid escaping the system from around the piston). In addition, the ‘Race’ brake now gets a magnesium lever body and caliper, a carbon lever, and titanium hardware to further reduce weight. Whereas the Trail brake has aluminium caliper and lever bodies and a ‘carbon/alloy’ servo wave lever.smith-XTR-2183 The new XTR rotors have adopted the ‘Freeza’ technology first introduced in the Saint range. These rotors take the ‘ICE’ heat dissipation a step further by introducing wavy cooling areas to the rotors that Shimano claim will reduce temperature build up by 50°C.

shimano xtr RSA-1787 Wheels XTR ‘Race’ wheels will come in three options, and the ‘Trail’ wheels will come in two options. All will feature carbon/alloy rims (an aluminium core wrapped in carbon). Race option one is a tubular 29” wheel that will probably only appeal to a select few hardened races. Race options two and three will be clincher wheels either 27.5” or 29” in size with a 20mm internal width rim and finally the Trail options will be both a 29” and 27.5” wheel with a wider 24mm internal width rim. Hubs are said to have new improved and lighter bearing axle assemblies.

M9000 Initial ride impressions Over the course of the weekend we not only got the chance to take the new XTR variants out for a casual trail ride but we also raced a 60km stage of the Cape to Cape event. This gave us a chance to consider the new components both at our leisure and also in the environment and conditions for which they’re best suited: racing. As a single chainring convert, I'm always a little remiss to get back on board a bike with dual or triple chainrings. On our initial trail ride I found that I wasn’t really utilising both rings up front and had to consciously do so in order to feel I’d tested the shifting out. On race day though, I quickly came to appreciate having the extra gearing as the course was a mix of long, flat, fast sections peppered with singletrack. I found myself sitting in the big ring most of the time but dropping down into the small ring to tackle surprise tight corners, quick climbs, holdups due to slower traffic, and the eventual decline in my energy levels. This mix of trail and especially the hard-packed road sections meant that a single chainring would have been insufficient as the gear range would never have been enough.

Shifting both front and rear was smooth and consistent (as you’d probably expect from new XTR). The lever action did indeed appear to be easier than past iterations but there was also a noticeably longer action required to shift gears. The first few shifts felt a little awkward to me, but by the end of our trail ride on day one I’d completely forgotten about this and didn’t recall it until I sat down to write this. For the record I’m a bit of fan boy when it comes to Shimano brakes, but I’ve always chosen to run the trail brakes as I like the additional immediacy and feel for power that you get from the servo-wave system. However over the weekend I spent most of my time on the Race brakes and grew to appreciate the modulation and simplicity they offer. The riding we did was never tough enough to really test the braking, but the feel, action, and consistency from the Race XTR’s seemed to be ideal for the riding we were doing.

A couple of days riding hardly constitute a thorough test, so I’m going to park my thoughts on the new XTR M9000 at this point and revisit them once I’ve done a little more riding.

Of course the big news from Shimano this year is the introduction of Di2 electronic shifting, I’ll cover off my first impressions of this in the next instalment . . .