Bottom Brackets

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.

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

- Simple and reliable square taper bottom bracket - Replaces both BB-UN26 and BB-UN55 - Sealed cartridge bearings - Cr-Mo axle - For bicycles equipped with a chain case, select BB-UN300-K - For E-type front derailleur compatibility, choose BB-UN300-E - Fixing bolts not included; Shimano FC-E6000 bolts suggested

Shimano Dura-Ace BB92, BB9000 Hollowtech II Bottom Brackets - Bottom Bracket Shell I.D.: 1.37" - Defined Color: Black - Weight: 65 g - Spindle Interface Type: Shimano Hollowtech II

- Tiagra-level Hollowtech II bottom bracket - Compatible with all road Hollowtech II cranks

Shimano's BB-UN55 Square Spindle Bottom Brackets are the unofficial standard for English-threaded cartridge bottom brackets. Quality, value, and durability come together to keep you cranking for many, many miles. - Fits JIS Square-Taper Cranksets - Hollow spindle - Crankarm fixing bolts not included

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.

Pressfit Model: • For use on BB86/92 bottom bracket shells • Compatible with 24mm spindle Hollowtech II cranksets • BB Shell Width (mm): 92 mm • BB/Frame Interface: BB86 , BB92 • Bottom Bracket Shell I.D.: 41 • Defined Color: Black • Spindle Interface Type: Shimano Hollowtech II Threaded Model: • Includes 3 x 2.5mm spacers • Includes TL-FC24 adapter tool • Reduced size for light weight • New seal construction for smoother rotation • Requires TL-FC34 or included TL-FC24 adaptor for installation & removal • BB Shell Width (mm): 68 mm • BB/Frame Interface: English • Defined Color: Black • Spindle Interface Type: Shimano Hollowtech II • Weight: 77 g