XTR GOES 12 SPEED

Shimano unveil new lagship group

Shimano’s new XTR M9100 isn’t just an update of their flagship groupset, but a complete redesign from the ground up, aimed at XC, marathon and enduro riders. Here are the key changes.

Rear hub

To make space for the extra sprocket, Shimano have had to redesign the freehub, devising a new ‘Micro Spline’ fitting system – which means you won’t be able to run any of the new XTR cassettes on your existing hub. They’ve also replaced the pawls of the previous XTR hub with a ratchet system to reduce drag and create a virtually silent freehub.

Crankset

There’s a new crankset to accompany the move to 12-speed, which uses a directmount chainring (30t to 38t) to save weight. Enduro riders can add a neat XTR chain guide for extra security. A 2x12 version of the crankset will also be available (38/28t). Both use Shimano’s proven ‘HollowTech II’ aluminium arms.

Cassette

The most significant change comes in the form of a new 12-speed cassette (Shimano’s first), available in 1051t and 10-45t versions. These have been designed to minimise the steps between gears, to help riders keep a consistent cadence. The former outdoes main rivals SRAM with one extra tooth on the largest sprocket, giving a 501 per cent range, versus SRAM Eagle’s 500. Shimano have combined three metals – aluminium, titanium and steel – to find the best balance of weight and durability. There’s also a new 11-speed cassette (with 12-speed spacing), for riders wanting to shave off a few extra grams.