Park tool bottom bracket tool bbt29the bbt 29 is a double ended bottom bracket wrench designed to fit 16 notch bearing cups with an outside diameter of 39mm e g shimano dura ace 9000 series and xtr 980 series as well as 16 notch bearing cups with an outside diameter of 48 5mm e g fsa megaevo features removes bottom brackets with 16 notch bearing cups with an outside diameter of 39mm as well as 48 5mmbuypark tool workshopfrom chain reaction cycles the worlds largest online bike st