The Shimano BB-MT501 is an English (BSA) threaded bottom bracket built for Hollowtech II cranksets on mountain bikes. Improved sealing and smoother rotation keep the bearings protected from dirt and moisture, supporting efficient power transfer from the crank to the drivetrain.
Aluminum threaded cups fit into standard BSA shells across both common mountain bike shell widths, without needing an adapter or spacer kit. This makes the BB-MT501 a straightforward upgrade or replacement for MTB frames running a threaded, English-style bottom bracket shell.
Quick Facts
| Feature |
Specification |
| BB Shell Width |
68mm / 73mm |
| BB/Frame Interface |
English (BSA) |
| Crank Spindle Diameter |
24mm |
| Spindle Interface Type |
Shimano Hollowtech II |