Shimano UN55 73 x 122.5mm Square Taper English Bottom Bracket - Walmart.com
Amazon.com : Shimano UN55 BB Square Taper Bottom Bracket (68x113mm) : Bottom Bike Brackets And Accessories : Sports & Outdoors
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
BB-UN55 vs BB-UN300 - which is the better square taper bottom bracket? - restoration.bike