Shimano Bottom Bracket BSA 68mm 122.5mm - Silver

Built for smooth pedaling and long service intervals, the Shimano BB-UN300 is a sealed cartridge bottom bracket featuring a proven JIS square-taper spindle for easy compatibility and rock-solid reliability. It threads into BSA (1.37" x 24) 68 mm shells, utilizes a steel axle for strength, and pairs aluminum (left) / aluminum-steel (right) cups with a sealed bearing unit that effectively resists water and grit. A built-in chainline stabilizer helps keep shifting crisp, making this a smart, low-maintenance replacement for commuting, trekking, and MTB bikes.

- Shimano BB-UN300 sealed cartridge bottom bracket for BSA 68 mm frames with JIS square-taper cranks
- Steel spindle and sealed bearings deliver durable, low-maintenance performance in all weather
- Aluminum / aluminum-steel cups provide secure, creak-free fitment and long service life
- Chainline stabilizer helps maintain precise shifting and drivetrain efficiency
- A reliable replacement for road, trekking, and MTB builds using square-taper cranksets

Specifications
Brand: Shimano
Model: BB-UN300
Type: Bottom bracket
Width: 68mm
Length: 122.5mm
Color: Black