Thread together bottom bracket for frames using the PF30 bottom bracket standard. Two machined aluminum cups thread together keeping the bottom bracket stable in the frame, increasing bearing life, and simplifying maintenance. This means no more creaking, smoother operation, longer bearing life, and really quick bearing replacement.Specifically designed for installing 24.00mm spindle diameter cranks (Shimano, Etc.) in PF30 (46mm ID BB shell) frames without the need for any adapters.