SHIMANO UN55 BB Square Taper Bottom Bracket for sale online | eBay
Shimano UN55 Square Taper Bottom Bracket - Cambria Bike
Shimano BB-UN55 Square taper Bottom Bracket for sale online | eBay
What is the difference between this Shimano BB-UN50 and the BB-UN55 ? The former is hard to find for sale, the latter seems to be found everywhere : r/bikewrench