Shimano UN55 Square Taper English Threaded Bottom Bracket

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