Headset and Stem

[EdVanSeveren]

Alex, I can't seem to get my headset correct. I'm not sure if its the headset, or the stem I'm doing wrong? After all is tightened, my handlebars turn, but my wheel doesn't. Its driving me crazy! Please Help! Ed

[cyclerUK]

What kind of stem / headset. Is it a quill or A-head?

If it's a quill then pull it out of the steerer tube and see if the "wedge" is working O.K. (I have had a steerer tube snap and obviously it wouldn't turn, but as you lift the frame the forks would drop down.)

If it's A-head then are you tightening the side bolts at the rear of the stem? Or, there could also be a shim missing.
Have a good look at what's happening and you should be able to pin down the problem.