BB-UN55 vs BB-UN300 - which is the better square taper bottom bracket? - restoration.bike
Shimano UN55 68 x 118mm Square Taper English Bottom Bracket | Green Mountain Bikes
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
Shimano BB-UN55 bottom bracket Italian thread 70 - 107 mm - York Cycleworks