Shimano XTR M9100

$500, 12-speed cassette; $250, front hub for straight spokes with 110-mm O.L.D.; $440, freehub for straight spokes with 148-mm O.L.D.; bike.shimano.com

In May, Shimano released a major update to its top-end mountain bike component line, xtr. The lineup includes new drivetrain options. The Japan-based company now has a 12-speed cassette. Actually, it has two: one that ranges from a 10- to a 51-tooth cog, the other from 10 to 45. Both can be run with a single ring at the crank; the 10–45 can even work with a two-by setup. The hubs in the xtr range come in Boost spacing – with over-locknut dimensions of 110 mm for the front hub and 148 mm for the rear – and non-boost spacing options. They’re quiet, too. Shimano’s Scylence technology in the freehub means there are no ratchet sounds when you’re freewheeling on the trail. Other riders might not even hear you coming.