Broadly speaking, hydraulic disc brakes designed for bicycles will use either a mineral oil fluid, or an automotive DOT fluid. Genuine Shimano Mineral Oil is the only fluid compatible with Shimano brakes.
- 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
