SHIMANO UN55 BB Square Taper Bottom Bracket Review Posted by Pelicandy October 1, 2018 in Drivetrain Components Bottom Bracket Fit – 68mm BSA of ENG Sealed cartridge bearings The Shimano BB-UN54/55 Square Taper bicycle bottom bracket gives you reliable strength for square tapered cranksets. Random Products Shimano 8-Speed Chain Pins (Bag of 50 Pins) Review USA Made 130mm BCD 5-Bolt SharkTooth Pro CXR Road/... TerraTrike 13t Deluxe Idler Review SRAM XX1 BB30 1X11-Speed 175 168 Q-Factor with 32T... Cycling Outdoor Recreation Parts & Components SHIMANO Sports & Outdoors