The quality and performance-oriented Shimano BB-UN300 cartridge bearing bottom bracket features a JIS square taper mount and is designed for frames with BSA thread and 68/73 mm shell width. A stabilizer ensures a constant chain line.

Features :

-Fits JIS square-taper cranksets

-Crankarm fixing bolts sold separately

-Hollow spindle

-Adapter: aluminium (left), aluminium / steel (right)

-Axle: steel