You, or more specifically, your choice of frame, motivated us to address challenges related to bottom bracket installation and durability – thank you. We embraced the task to improve upon so-called bottom bracket standards to give you the UBB4630. Crafted from 7000 series aluminum alloy, the UBB4630 uses a threaded sleeve to lock both cups in place – without having all the locking effort rely on the press fit shell, thus providing a uniform spin and avoiding undesired noises. The flush fitting in the press fit region prevents bearing overload and also improves bearing alignment for a longer bearing life. The external bearing location affords a smoother spin and increased BB shell stiffness for BB386 EVO. The internal sleeve also prevents cable guides from rubbing against rotating parts.