Race Face Bottom bracket adapter, 83mm BB to 68/73 shell Review Posted by GiantPandaisy July 3, 2018 in Drivetrain Components This fits your . Make sure this fits by entering your model number. Shell Size: 83mm Retrofits an X-Type 83mm bottom bracket to fit a 68/73mm shell. Cycling Outdoor Recreation Parts & Components RaceFace Sports & Outdoors