Shimano's Square Tapered Bottom Bracket BB-UN300 is a standard BSA style bottom bracket with various shaft lengths.
The BB-UN300 Square Tapered Bottom Bracket was released by Shimano as a successor to the previously manufactured BB-UN26 and BB-UN55.
BB-UN300 has BSA standard and various different axle lengths are available, soIt covers a wide range of bicycles, from touring bikes, city bikes, old road bikes and mountain bikes.
* Crank bolts are not included.
Shell width: 68mm
Axle length: 107mm, 110mm, 113mm, 117.5mm, 122.5mm
Axle type: Square taper (JIS)
Axle material: steel
Bottom bracket cup material: aluminum (left), aluminum / steel (right)