Just installed a new fork/headset on my bike. I haven't put a stem on yet but I'm noticing a very small wiggle in the fork-like the headset is loose. The headset is a Cane Creek IS-2 (it simply drops in). Do I just need to install a stem or does this sound like the frame has a problem?

you need slide the stem on, and before tightening the stem bolts, tighten the top cap on your steerer tube, until the wobble goes away, but the headset doesn't bind. then tighten the stem bolts.

Your fork shouldn't be able to just slide in, in fact it's very very hard to push it in. What I think happend was you got a headset that was to big, that was my problem. My suggestion is bring your bike (with the fork) to a bike shop and have them find a headset that will fit. Because like I said, your fork shouldn't just slide in. No worries though, your frame should be fine. Just don't ride it with the loose fork, that could mess up your frame.

Chaves

p.s. be carful not to tighten the stem cap to much, you may bend the starfingle inside the fork which is a pain in the ass to replace unless you have a special tool.

I think that the ease of fork intallation really depends on the particular make/model of headset/fork/frame. I went to this one bike maintence class, and we were talking about headsets and how to service them. The mechanic took a specialized sequioa (completely stock, almost brand new) and the fork just slid right out, along with the bottom set of bearings.

My new Ouzo Pro fork in an FSA headset does the same thing. Believe the bearings need slide easily (without play) on the steer tube so that you achieve the right preload when you torque the top cap.

Your fork is bound to feel a little loose because you can't set the pre-load on the headset bearings with the top cap until you slide the stem and any spacers into place. Once you do that, I suspect everything will be fine.

My Soloist has no problem with the forks sliding in/out with extreme ease and of course the wobble is there until you do as the Phatman says......