Park bbt90 bb90 bottom bracket bearing tool set a quick and easy way to remove bearings from press fit type bottom brackets with an inside diameter of 37 41 mm bb90 bb92 shimano press fit sram press fit gxp the bbt 90 works similar to a small head cup remover to safely extract low profile bearings from inside the bottom bracket shell as the tool slides through the shell it expands behind the bearing once the tool is in place the bearing is removed by tapping on the top cap with a ham