RockShox SID Ultimate Race Day 2 Suspension Fork - 29" 120 mm 15x110 mm 44 mm Offset Electric Red 2P Remote D1. Climb mountains. Charge descents. The RockShox SID Ultimate isnt like other XC forks. It is lighter than ever with a formidable 35mm chassis that holds the line when youre on the edge. The Race Day 2 damper provides efficient Pedal positions all at your fingertips. SID Ultimate adapts to everything from full-gas cross-country to sporty backcountry loops thanks to a new higher-volume DebonAir spring thats supple at the top of its travel with tons of tunability.