Bottom Brackets

Shimano's 105 Bottom Bracket Cups are compatible with Shimano's integrated cranksets and bicycles with threaded bottom brackets. The cups are made of lightweight aluminum and the excellent Shimano bearings are sealed for maximum durability. There's also a nylon sleeve for additional bearing protection.

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

Shimano's Dura-Ace Bottom Bracket Cups are perfect for Shimano's Dura-Ace Crankset. They feature super-smooth sealed bearings, a plastic sleeve for additional protection, and they come in English and Italian threading.

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.