I often find that once I've gotten an exandper type stem bolt tightened firmly, that sucker never want to let go. I mean that. Never. It can be quite a feat to loosen an older expander bolt. I'd advise using a light oil on the expander just to make sure it doesn't permanently bind to the quill.

I'll double down on my advice and that of mrkwkr above: make sure that the stem is not too low in the fork - as your quality bike might have a slight taper that is preventing the expander from sliding between the quill.

If you find a domestic (in the U.S.) source for expander-type bolts for stems, you've got to share the contact details with me! The are available all over the world, it seems, except here in the U.S. If i can't find any extra parts this next week, I'm going to import some from abroad myself. It will be worth it to have the extra stock on hand.

gritereck, if you're looking for a Flying Pigeon (warning: min inseam to stand over top tube is 32 inches), I just opened a bicycle shop in the L.A. area called "Flying Pigeon LA"

http://flyingpigeon-la.com