Jammed stem

Quoted post said:

Originally posted by rickstarrunner
I can't remove my stem from my steer tube. I've managed to wiggle it about 1/2 inch from its original position, but am unable to move it in any direction now. I've tried bending the stem open more with a screwdriver, but I'm afraid to try to hard as I don't wanna mess anything up. Help! Eric

Yikes...

What's the history of this stem/steerer assembly? I mean, was this recently built up, or is this an older rig that may have seen some damage?

Sheldon Brown's website has a page of useful tips (here) for dealing with stuck seatposts; I wonder if some of these approaches might be applicable. They may, depending on the condition and history of your bike, steerer tube, and stem.

What's the story?

I only recently acquired the bike used (from a friend) so I don't know the exact history or age of the bike, but there's no rust or anything else abnormal. It looks in great condition, but I think the stem has been on the steer tube for a couple of years at least.

Quoted post said:

Originally posted by rickstarrunner
I only recently acquired the bike used (from a friend) so I don't know the exact history or age of the bike, but there's no rust or anything else abnormal. It looks in great condition, but I think the stem has been on the steer tube for a couple of years at least.

It may help to specify the make and model of the stem in case someone has specific experience with the particular clamp.
At first glance I thought maybe you had a quill type stem, but can see that you are trying to open up an external clamp now.
Any problems in relieving tension on the headset assembly?
I am assuming that you do NOT have a carbon fiber steerer tube?

Zinn & the Art of Road Bike Maintenance has these suggestions:

Remove the bolts, thread them in from the other side. Instert a coin into the slot between each bolt and the opposing unthreaded side of the stem. Tighten each bolt to spread the clamp slot open.

If you have a stem with a single bolt ahead of the steering tube, loosen the bolt and tap it with a hammer to free the wedge. You may need some penetrating oil.

Thanks all for the advice, I got it off today by my original method. The bike's former owner recommended continuing prying the clamp open with a screwdriver, which eventually worked.