Foundation Headset Cup Removal Tool Medium Knock it out! If you have a press-in headset on your frame and want to replace it with something new, you'll need a tool to remove your existing headset. The Foundation Headset Cup Removal Tool Small is designed to work with 1-1/4" and 1-1/2" headset standards. It has a nominal outer diameter of 28. 6mm. Features Removes headset bearing cups using 1-1/4" and 1-1/2" headset standards Nominal outer diameter of 28. 6mm Use with a hammer or mallet to knock out the bearings | Foundation | Headset Cup Removal Tool Medium Headset Cup Removal Tool Medium