Shimano XTR 10 Speed Dyna-Sys Drivetrain M985
Based around the wide-range 10 speed cassette and 2-ring crankset, the XTR Race M985 groupset is lighter, smoother and better suited to the demands of Elite XC racing than ever before. Introduced as the new flagship 10 speed component line, Shimano have brought a number of new shift technologies to the XTR line with improvements across the board including tighter ratios for faster shifting, redesigned pivot geometry for more linear gear changes and a new Vivid Indexing system that increases feedback through the shifter paddles. While many of these improvements lie beneath the surface, the most noticeable change to the M980 group is the addition of a 2-ring crankset that gets the M985 moniker. As SRAM have been pushing ahead with their 2x10 XX groupset, Shimano have hit back with the latest XTR with both a triple and double chainset so that riders can choose the gear range they require. While a 3x10 setup is always going to have more gears, many riders are heading towards the 2x10 arrangement thanks to the availability of wide-range cassettes, such as the 11-36t XTR unit, that allow you to use all 10 gears out back, with less need to shift up front. The main benefits for using a 2x10 drivetrain are that it is lighter, simpler and faster shifting as you can use a Medium cage rear derailleur and also reduce chain length for less bouncing around on rough descents. If you don't use all of your current gears, there is a good change you can experience the slicker shifting that comes with a 2x10 setup, all with a more usable range. The beauty about the latest XTR line is that you can mix 'n' match the components between the "Race" and "Trail" versions to get the perfect setup for your bike. All up, the newest XTR is faster, smoother, more efficient and better suited to a wider variety of riding styles thanks to its inbuilt adjustability and gearing options.

From Shimano:

"If you expect every bit as much out of your equipment as you invest in your training, then you’re in the right place. The new XTR Race group doesn’t just ask to be pushed at race pace, it demands it. Want to race on a triple or boost your brake power even further? Don’t be afraid to personally tune your ride with components from the XTR Trail catalog of cross-compatible options."

So what exactly have they improved on?
Well aside from the obvious inclusion of a 10 speed cassette, Shimano have made several key changes to imrpove shifting on your bike. The XTR Chain itself is now an asymmetric number, with one side that is made to work optimally with the shifting pins and ramps on the front cranks as you move into a bigger chainring, and the other side is made to work with the shifting ramps as it climbs up the cassette. This is particularly noticeable when shifting under load, as the 10 speed drivetrain is so much quicker and more accurate than previous generations.
The XTR Cassette maintains its Titanium construction for the 5 biggest cogs, though now has a larger spread of gears than the old M970 version, with an 11-36t option giving you a super low gear for technical climbing and being particularly popular with bigger-wheeled 29er bikes. They still have an 11-34t option which will be better for XC racers, and both cassettes feature ratios that are tighter due to the extra cog.
With the change in ratios at the back, the XTR Crankset is now available in a dual-chainring model in addition to the traditional triple chainset. You can choose between a 38-26t ratio or a 40-28t setup depending on what gears your terrain requires, though we would recommend the smaller ratio for 29er and trail riders who still need to climb. Shimano have designed the new 10 speed drivetrain to allow you to use the entire cassette range in each chainring, with no fear of crossing the chain.

And what does this mean out on the trail?
Well the main benefit is that you'll reduce the amount of shifting up front, which most people will agree is a very good thing. With a bigger spread of gears at the back, you can spend more time using a single chainring with less need to shift around up front, leaving you to spend more time focussing on the trail ahead. Being able to use a shorter chain and a Medium cage rear derailleur  with the 2x10 setup improves overall chain tension that aids in snappy shifting, while also being less prone to bouncing around and potentially derailing. If you're riding particularly technical trails and/or you're on a longer travel dual suspension bike, we would highly recommend the M985 Shadow Plus rear derailleur option, as it provides a stronger tension spring for the pulley cage that reduces chain slop even further and acts like a pseudo-chain device. Thanks to the tighter cassette ratios, shifting is smoother than ever before and believe it or not, the 10 speed chain is both stronger and less prone to stretching than the 9 speed equivalent. We're big fans of the Vivid Index shifting feel as it closes the gap on the super-snappy SRAM trigger shifters, while still maintaining the silky and stealthy feel of XTR.


The Shimano XTR M985 Groupset includes:

• Shimano XTR Crankset: M985 with 38/26t or 40-28t chainrings
• Includes XTR Bottom Bracket
• Shimano XTR Shifters: Choice of standard bar clamps or integrated I-Spec Mount (for use with M980 brake levers)
• Front XTR Derailleur (Hi Clamp, Low Clamp, E-Type or Direct Mount - check your bikes specifications) 
• Rear XTR Derailleur: Shadow or Shadow Plus option (Medium cage for 2x10 setups)
• Shimano XTR 10 speed Chain
• Shimano XTR 10 speed Cassette (11-34t or 11-36t ratios available)

Shimano XTR components get you World Cup level technology