Shimano BB-ES51 BSA Bottom Bracket

Tried, tested, and trusted. The Shimano BB-ES51 is a durable Octalink V2 cartridge bottom bracket designed for Shimano Octalink V2 splined cranksets — delivering reliable, low-maintenance performance for MTB, trekking, and compatible road applications.

The oversized 22mm hollow chromoly spindle is stronger and stiffer than a traditional square taper axle, while the Octalink V2 eight-spline interface creates a rigid, play-free connection between the spindle and crank arms for efficient, direct power transfer. Anti-corrosion treatment inside the hollow spindle adds long-term durability, and the sealed cartridge bearing assembly keeps dirt and moisture out for extended service life with no adjustment required.

BSA English threaded cups make installation and removal straightforward with a standard bottom bracket tool. Available in both 68mm and 73mm shell widths, with three spindle lengths to suit your crankset and frame combination.

Compatible with Shimano Octalink V2 cranksets including Deore LX FC-M752/751, FC-M571, FC-M510, FC-M440 and Tiagra FC-4401/4404. Not compatible with Hollowtech II, XTR, or most road cranksets. Crank fixing bolts sold separately.

Key Features:
- Shimano Octalink V2 splined interface
- 22mm oversized hollow chromoly spindle
- Anti-corrosion treatment inside hollow spindle
- Sealed cartridge bearings — maintenance-free
- BSA English threaded cups
- Compatible with 68mm and 73mm shell widths
- Available spindle lengths: 113mm, 118mm, and 121mm
- Crank fixing bolts sold separately