When it comes to lightweight, high-end suspension, RockShox's SID XX is pretty much THE fork for cross-country riders and marathon racers. It's light, it's stiff, and its Dual Air chambers and XX Motion Control DNA damping are fully tune-able for a custom feel and a dialed ride. The Solo Air spring keeps both the positive and negative air chambers in equilibrium for a plush, predictable ride that you can set up in seconds. The chassis features an aluminum steerer, magnesium lowers, and post mount disc brake bosses, so the SID XX is ready to conquer any distance. And for those long fire road climbs, sprints during races, and riding from your house to the trail, you've got RockShox's XLoc hydraulic remote lockout for the ultimate in efficiency.