I've noticed the same issue, neck pain trying to look "up" riding a flat bar road bike with mtb gears. I bought it at a LBS new many, many years ago. I've never had a true fitting, and despite riding a decent amount, didn't discover until just recently that my seat had been set far too low. I've raised the seat, but my neck was still pretty sore on my most recent 40 mile ride, where I was working fairly steady to try to keep up with a companion that has more road bike style gears. I'm of course working much harder than they are, so while I would certainly like to be more comfortable on the bike I have, I'm shopping for a different one, but very undecided as to what direction to go.

I'd like road bike gearing, but am unsure if another hybrid with road bike gears is the way to go, or if I go radically different and get a road bike? Will the neck pain issue be the same, worse on a road bike? I've been to 3 LBS looking, but most do not seem to have bikes in my size (I'm 5' 6 1/2" wit 31 inch inseam), at least not in the models I've liked so far. I sat on a 50cm trek road bike that felt ok sitting still in the store, but have no idea how it would feel if I were to be on it a couple of hours. Is it the acme of foolishness to look at used bikes on CL from owners that are approximately the same size?