Originally Posted by Aeroplane
Personally, I like a stem to stay in place. If you clamp to a threaded surface, you are losing about 2/3 of the clamping area, and completely ****ing up the fork.
You can probably trade your threadless headset and stem for a threaded headset and quill stem. Hell, you can probably make money on the deal. Why not do it right? It seriously boggles my mind.
I've never seen a quill stem that stays in place as well as any threadless stem. I doubt clamping over threads would make that much difference. I dare you to try this with any properly tightened threadless stem: hold the front wheel between your knees, then grab the handlebars and twist. I bet the wheel will flex before the bars move. Now the same thing with any quill stem. I like quill stems, especially for their ease of adjustment. I'm not bashing them, but they sure don't stay in place as well as threadless, even if you do clamp over threads.