evo.com | Shimano Bottom Bracket > Turn, turn, turn. The Shimano SM-BB52B Hollowtech 2 BB Bottom Bracket was made to spin. This Deore level BB delivers efficient performance and is sealed very well. From the standpoint of water. Large Sealed Bearings Shimano 24mm Spindles Threaded Bottom Bracket 68/73mm Shell Width Better Sealing | Shimano SM-BB52B Hollowtech 2 BB Bottom Bracket 2022 in Grey