Shimano's top line XTR mountain bike group is getting updated, lighter disc brake components, a lighter bottom bracket, a more durable chain and a super light carbon tubular 29er wheelset.
The new parts are part of the XTR Race sub-group, intended for cross-country racing, but are largely interchangeable with the XTR Trail subgroup.
The Japanese component giant has shaved 40 grams per wheel off its M985 Race brake by using a magnesium caliper and master cylinder, carbon fiber brake lever blades and titanium fasteners. The BR-M987 caliper is compatible with ICE Technologies finned disc brake pads and the BL-M987 lever is compatible with Shimano's I-Spec lever integration system.
The SM-RT99 finned ICE Technologies disc brake rotor, first used on the World Cup downhill circuit, is now available at the XTR level for cross-country use. The rotor improves heat management through the use of aluminium cooling fins between each spider arm. It's available in 180/160/140mm sizes.
The new SM-BB93/SM-BB94 bottom bracket will be added in threaded and press-fit options that are lighter by 19 grams, while offering less rotating friction and improved seals.
And the new CN-M981 HG-X mountain bike chain uses Sil-Tec, a surface plating technology Shimano claims offers an increase in performance and durability. The treatment is used on the new Dura-Ace 9000 chain. The mountain bike version is said to better hold lubrication and shed mud than the earlier XTR CN-M980 chain.
Carbon tubular 29er wheels
The new limited edition XTR WH-M980 carbon tubular 29er race wheels are "race day" items for cross-country athletes. The full-carbon offset rim tips the scales at 280 grams. The wheels use 28 spokes and will be available in 15mm front and 12mm or QR rear, and splined Center Lock rotor mounting. The wheel set weighs 1,349 grams for the front 15mm/ rear 12mm axle wheel set and 1,298 grams for the front 15mm/quick release rear axle wheel set.
