Sometimes called a headset slammer, you grab it with a fist and a flexed bicep and pound the crown race onto the steer tube’s shoulder. Grease the shoulder first, and slam it on with two to four hard hits, as needed. If after four it’s still not level and seated, ask somebody stronger to do it for you. But this tool, super heavy, is as pro-quality as any we’ve seen, and seriously—if you can’t do it with this, it ain’t the tool. Comes with fittings for a range of headset sizes.
