Are you considering the Full Speed Ahead Gradient Crankset? If so, you'll need to use this FSA bottom bracket with your new crankset for optimal performance. (Stock Polygon bikes do not use this Bottom Bracket) DESCRIPTION BB392 crank to BSA frame FEATURES No REFERENCES CODE TYPE 200-3213 BB ck BB392EVO MTB to BSA 68/73mm BB-EVO7000 SPECIFICATIONS Type Bottom brackets Manufacturer FSA