Bottom Brackets

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

Cartridge-style bottom bracket for use with E-Type front derailleurs. - Smooth rotation - Square taper spindle - Sealed cartridge bearing assembly

Shimano's Dura-Ace Bottom Bracket is perfect for Shimano's Dura-Ace crankset. It features durable composite construction, super-smooth sealed bearings and a plastic sleeve for additional protection.