- 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
The uninterrupted shifting experience of the DURA-ACE R9200 12-speed cassette range lets you climb, sprint, and push your limits without stopping to think about your next gear change.
