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
Středové složení SHIMANO BB-UN55 - 68mm
SHIMANO UN55 BB Square Taper Bottom Bracket for sale online | eBay
Shimano BB-UN55 Bicycle Bike Square Bottom Bracket 107-127.5mm Sealed Cartridge Bearing - AliExpress Sports & Entertainment