Campagnolo Record RD4-REXS 10-Speed Short Cage Carbon Bike Rear Derailleur. Campagnolo’s legendary engineering: the Record Carbon Titanium 10-Speed short-cage rear derailleur. Widely considered the absolute pinnacle of Campagnolo’s mechanical road groupsets, this mid-2000s masterpiece is brand new, never mounted, and remains in its original factory box. Speed Compatibility : 10-Speed index matching. Cage Length : Short cage. , primarily designed for classic double road or compact cranksets. Weight : 184g to 187g, making it exceptionally lightweight for its era. Maximum Cog Size : 26 teeth. Total Capacity : 27 teeth. Premium Materials : Fabricated with an aluminum body, a 90° carbon fiber outer parallelogram plate, a carbon fiber outer pulley cage plate, and full titanium hardware including the b-pivot, p-pivot, and cable clamp bolts.