Looking for a PF30 BB with replaceable bearings? The Wheels Manufacturing PF30 Bottom Bracket has a CNC-machined aluminum shell for precise bearing alignment and frame fit and the replaceable Enduro bearings. Made in the USA and featuring a 2 year warranty, this BB could be the answer that you have been looking for. Grade 3 silicon nitride balls ground to .00003 for unmatched smoothness and efficiency. R-64 hardened, magnetite coated, polished, cryogenically treated 52100 alloy bearing races for long-term performance. Silicone VV-type 2-lip non-contact labyrinth seals for excellent bearing protection with minimum friction. Long-lasting Rheolube synthetic grease helps prevent contamination. Nylon/graphite retainer to further minimize friction.