PF4630 Bottom BracketThis Bottom Bracket is when you have a PF30, BBright, or 386EVO shell frame and want to install a BB30 crankset into the frame. All have a 46mm inner diameter and smooth insides, though the widths vary from 68mm to 86mm. The crank has a 30mm diameter spindle. This bottom bracket features nearly zero loss of power due to friction, thanks to the bearings. The bearings have super round, super smooth CeramicSpeed balls rolling on hardened-steel races. The Coated version has a metallic coating laid onto the races, making them even harder and smoother, resulting in longer life and lower drag. They come installed in cups.