Park tool bbt90 bb90 bottom bracket bearing toolpark tool sets the industry standard for workshop tools and their bbt 903 bottom bracket bearing tool maintains that standard it is designed for installation and removal of bearings and bearing units used in press fit bottom bracket systems the bbt 903 includes a bearing removal tool and two bushings which are used in conjunction with a park tool bearing press to press the bearings into the bottom bracket shell features suitable for bb90 b