Shimano Puts XTR on a Diet, Intros New Brakes, 29er Carbon Tubulars, More
While many may have been expecting the release an 11 speed or electronic mountain bike drive train, Shimano’s latest product release is all about weight – the weight of the XTR Race component group to be specific. Thanks to the introduction of new brakes, bottom brackets, a chain, and tubular carbon 29er hoops, Shimano’s top tier build kit continues to hone the racer’s edge.
In addition to the new, lighter XTR parts there were a few other goodies floating around the launch like a new 650b wheel…
All of the new parts are exciting in their own rites, though for most of us the most interesting bit of new kit are the all new M987 disc brakes which shave 40 grams per wheel off the previous XTR M985 Race disc brakes – which makes it the lightest XTR disc brake, ever.
Built with magnesium calipers and master cylinders for weight reduction and heat management, further weight is trimmed with the addition of (their first, ever) carbon brake levers and titanium and alloy fasteners throughout. According to Shimano, they had to crash and break a lot of carbon levers until they got to the point where it was a viable material that met their standards for production. The lever is apparently strong enough that if you crash hard enough to break it, you probably will have done damage to the rest of the brake as well.
Magnesium does not like heat, so when asked how Shimano made the material work for the new brakes, we were told that it was all a matte of heat management – basically that the Shimano Ice-Tech system keeps the heat down to a manageable level to use the Magnesium parts. M987 brakes will be shipped with standard pads to keep the weight down, though they will be compatible with the radiator finned pads and will be iSpec compatible as well.
To further help with dumping heat during braking, the M987 will be paired with the SM-RT99 aluminum finned rotor which has proven itself in World Cup Downhill competition. Now available at the XTR lever, the new rotor will be offered in 180/160/140mm options in Center Lock only and are said to lower the temperature an additional 40 degrees compared to the previous SM-RT98 rotors. Used together with the M987s you have one of the lightest, coolest running brakes Shimano has produced. According to Shimano, the addition of the cooling fin ripples allow the rotor to absorb the same amount of heat as the next size up in a traditional rotor. The rotor on the scale is a 140, but it doesn’t have the correct spider. The actual spider for the SM-RT99s will be hollowed out like the rotor on the bottom right, dropping the weight even further.
For the true XC racers in the crowd, Shimano will now be offering a limited edition carbon tubular wheelset in 29” only. Already proven at World Cup and Olympic XC mountain bike races, amateur racers can roll the same carbon tubulars provided you have the cash, of course.
Built with a crazy light 280g full carbon, offset rim, the WH-m980s have 28 spokes and a 36 point engagement freehub body. When it comes to hub compatibility, the front axle is only offered in a 15mm thru axle, while the rear is offered in 12×142 or standard QR, but is not convertible. Total weight for the wheelset is 1349 for the 15mm/12mm combo and 1298 for the 15mm/QR combo.
The drive train is not completely ignored, though additions are limited to the chain and bottom brackets. For 2014, Shimano is introducing the CN-M981 which they call a super narrow HG-X chain. Plated with a new technology termed Sil-Tec that was developed for Dura Ace 9000, the chain is said to hold lubricant longer, sheds mud better, and will run smoother for longer than the previous gold standard, the CN-M980. Essentially, it is the same chain with the same nickel plating, but with a new Fluorine component that increases the performance of the chain especially when cross chained. The coating will make its mountain bike debut with the XTR chain, but will find its way onto XT, SLX, and Deore chains in the future.
Bottom brackets also get some love with the introduction of the SM-BB93/94. The new BBs are said to be around 19g lighter and will be offered in both threaded and press fit options that claim lighter rotation and better sealing than before. This marks the first time that there have actually been different bearings between the road and MTB press fit bottom brackets.
Shimano Chain Guide
Ah, the elusive Shimano chain guide. It was brought out to show, and mentioned that they were starting to ship to athletes. Though, you probably shouldn’t hold your breath on this one as it sounds like the decision has been made not to bring it to market which is a bit of a bummer since it has some smart features – like the spring loaded lower guide. It’s also pretty light at 120 grams for the guide and 31 for the micro bash guard. But again, probably not gonna happen.
650b/27.5 XT Wheels
Something that is happening though, is Shimano’s recognition of the 650b. Hand delivered just before the show, XT is going 650b. Identical to the current XT wheels, just a bit bigger, the XT 650s will be rolling out with a selection of axle options along with some new thru axle XT 29er wheels not currently offered.
In addition to the few parts we got on the scale, Shimano provided their claimed weights for the new product below.
- XTR M987-kit w/G01A resin pad, w/o adapter, for front , 800mm, postmount, W/RT99S : 305 grams
- XTR M987-kit w/G01A resin pad, w/o adapter, for front , 800mm, postmount, W/O RT : 186 grams
- XTR WH-M980-F15+R12 : 1349 grams
- XTR WH-M980-F12+QR : 1298 grams
- CN-M981 HG-X, 114L, w/o ampoule type connect pin : 259 grams
- SM-BB93, thread type : 71 grams
- SM-BB94-41A, pressfit type : 58 grams