Joined: Feb 2012
Posts: 19,353
Likes: 5,471
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
A further thought- If you were to cut/grind away the upper headset nut and cone you'd free up the steerer inside the head tube. Then you's really find out how the stem was placed in/over the steerer. Really, don't do this until you're out of any other options. You're likely to find out that you have a traditional quill stem after all. Andy.