Coming from RockShox's SID family, the SID Ultimate 29inch Boost Fork is the top-level option for aggressive XC riding. It perfectly balances our go-fast tendencies with our desire to chase after trails with bigger hits and features. Stiffness is boosted over the featherweight SID SL thanks to a larger 35mm chassis, supported internally by RockShox's Charger Race Day Damper. Ultra-low friction SKF wiper seals offer lasting performance and an overall suspension feel, and its DebonAir spring employs a higher ride height for improved handling and confidence.