Originally Posted by
John D
If that is a smaller frame size I'll bet the stem adaptor/wedge got jammed down too low bottomed in the tapered or re-enforced interior of the steerer. You need to clamp a donor stem on there and whack from underneath the stem.
^^^Quite possible!
Perhaps first "loosening" the headset nut might free it or assist with additional efforts.
Might also explain why the wedge can't be knocked free(???).
I once had a stem quill pull free of the steer tube while accelerating from a stop light, while I was test-riding someone's very small-framed Schwinn Circuit.
The stem quill couldn't even be inserted to the point where the limit line wasn't visible, so some previous owner had filed a taper on the lower expanding end of the quill.
I had to cut the quill shorter, reduce the wedge cone diameter and extend the expansion slot in order to use the factory-original Cinelli 1A stem safely.