The FSA SL-K 386 BB30 Compact MTB Crankset. SL-K Has been the choice of professional riders and racers. SL-K products offer the the best combinations of lightweight, strength, and advanced technology for the the serious athlete who relies on their bike to perform without compromise. FSA ;s BB30 is lighter, narrower, stiffer and more durable than traditional bottom bracket systems. Oversized alloy spindles and bearings pressed directly into the bottom bracket shell offer weight savings up to 12%. In combination with a crankset for the BB30 bottom bracket standard new standards for stiffness to weight ratio will be reached. Advantages of the new system are: - lighter - stiffer - low Q-factor (narrower cranks, increasing ankle clearance) - more durable because of significantly larger bearings. ; UD Carbon composite arms with alloy spine ; AL7075 100% CNC chainring ; Cr-Mo steel chainring bolts ; Optimized for New 1x11 speed MTB systems ; Available for SRAM and Shimano 10 and 11 speed ; UD carbon finish ; BCD: 86mm ; Weight: 709 g ; Comes with the BB cups About FSA Cycling Express are huge fans of FSA products. The driving force of bicycle component maker Full Speed Ahead is well captured in their name. FSA stays ahead of the competition through design innovation and manufacturing expertise. FSA are truly a global company, with offices in the USA & Italy that collaborate to direct FSA ;s component development..