Okay, let's see if I can make a decent attempt to explain this: When I hold down the front break and rock the bike, there seems to be a slight knock-both felt and heard, coming from either the front shock or the headset, I can't tell for sure. Does anyone else have this and is this normal? Rides fine, I just noticed it when my friend pointed it out; he said the shock felt "loose", whatever the hell that means. Any info would help out.

Thanks

It's the headset / stem interface here's how to fix it.

1.Remove bolt and top cap to inspect steering column. Lubricate adjusting bolt and re-install cap and bolt by hand only. DO NOT TIGHTEN.
2.Loosen stem bolt(s) that secure stem to the steering column. Lubricate these bolts if they are dry. NOTE: DO NOT LUBRICATE INSIDE STEM OR ON STEERING COLUMN SURFACE.
3.Wiggle the stem side to side to see that it is loose. If the stem is jammed or rusted frozen to the steering column, no adjustment can be made.
4.Align stem straight to wheel and gently secure the top bolt. Stop when any resistance is felt.
5.Tighten stem bolt(s).
6.Check for play by pulling back and forth on fork. Turn the handlebars in different directions while checking for play. There may be play at this early setting. Use care when grabbing suspension forks, because the legs may have play. Grab upper portion of fork.

it could also be your brakes.

i know that on my bike, the headset/stem is all adjusted just fine, and i still get that little knocking and slippage if i pull the brakes and rock the bike back and forth. but if i try to move the headset by bracing the bike against a wall and rocking it, i get nothing.

if you look at your brakes, try to see if there is a slight (VERY slight) amount of play between the actual brakes and the posts they're screwed onto. i'm not talking about the pads...play between the mounting posts and the 'calipers' themselves. there really isn't anything you can do to fix this...maybe add a washer between the bolt and the brake arm...i haven't done anything about it, since i don't ride that bike very often...i suppose it could eventually rip the brake studs off the fork, but i doubt it.

if it turns out to be the only in the fork, your cartridges might be starting going bad...if your fork doesn't use cartridges, then i don't know what to say...

Thanks for the advice. I have disk breaks by the way, so I don't know if the whole brake theory applies, but I'll try it anyways. AS for the headset, man, I don't think I have the tools to take that thing apart. Looks like a trip back to the LBS. How big of a problem is this, by the way? Is it a big deal that could turn out to be a safety hazard, or is it just a mere nuisance?

Thanks again.

You don't have a set of allen wrenches? Fix it now before you wreck your headset or ovalize your frame

disk brakes won't cause that... i'm with raiyn. take it to a shop.