Standards • 2025-11-20
T47 Bottom Brackets Explained
The best of both worlds? Why T47 is taking over.
T47 is essentially a threaded version of PF30. It uses the same 46mm shell diameter but adds threads (M47x1.0). This solves the creaking issues of PressFit while maintaining the stiffness and crank compatibility of a large shell.
Internal vs External
T47 Internal (86mm width): Bearings sit inside the shell. Used on road bikes to mimic BB86.
T47 External (68mm width): Bearings sit outside. Used on adventure bikes to mimic BSA.