Chainrings and Bottom Brackets Rotor Rotor Press-Fit 4624 Bottom Bracket -20% $56.07 $70.08 Main Features Rotor Press Fit 4624 Bottom Bracket Adapter for mounting 24mm axle cranks on BB30 PF frames. Steel (black) 137g. Anodized aluminum, laser engraved. CNC lathe machined with AL 7075 T6 treated. Silicone seals and inner tube (less contamination, less maintenance). Add to cart