Bottom Brackets

Shimano BB-ES51 Octalink V2 Bottom Brackets - Fits Shimano Octalink V2 Spline Cranksets - Crankarm fixing bolts not included

BB-UN26 cartridge bottom bracket. - Smooth rotation - Square taper spindle - Sealed cartridge bearing assembly

• Lightweight seal structure removes grams • Durable anodized finish • Includes left and right hand cups, spacers, inner cover, and inner o-rings • Easy installation with TL-FC25 tool • Compatible with 24mm crank spindles • English, threaded: 68/73mm bottom bracket • Pressfit: BB86/92 bottom brackets

Shimano's Ultegra bottom bracket uses Pro Tour-proven technology for lighter weight and super smooth spinning, while still maintaining the same level of durability and stiffness. It's available in English, Italian, or Press Fit models.

Compared to the power transfer of the conventional square taper spindle, the 8-splined OCTALINK interface that connects the bottom bracket and crankset increases the strength and rigidity for the entire assembly.