Shimano Chaincase BB-UN300-K Square Taper Bottom Bracket

The Shimano BB-UN300-K is a square taper JIS bottom bracket specifically designed for use with a chaincase. This reliable component ensures smooth rotation and a stable drivetrain interface for MTB configurations.

• Precision Fitment: This 68×122.5mm MTB Double option includes a 0.7mm spacer to ensure proper alignment and clearance within the bottom bracket shell.

• Chaincase Compatibility: Specifically engineered as a “K” type model, making it the correct choice for bicycles equipped with a full chaincase.