I've never been the most confident rider out there, but have generally been able to stay upright and avoid crashes. I started riding again last year after a 10 year lay off and descovered I could no longer descend! As I live in the mountains this is something of a problem. The bike seems ok, no obvious wheel or headset problems. As I pick up speed the front wheel starts to violently shake. I think I'm so nervous that I get a death grip on the bars that starts the problem and then makes it worse.
Today I had the same problem during a high speed sprint on level ground. Is it me, the bike or both? I would like to get back to enjoying my rides instead of worring about crashing. Thanks, peon 402.

Okay, I give up - is this a joke? I guess you should coast freehanded to see how the bike steers. Riding rollers freehanded is another great way of determining frame/wheel track of any given bike.

It does sound like there's a loose hub or headset on that bike. Or a tight binding headset would cause stability problems as well. Check the frame-alignment, both wheels should be on the same plane

It could be something on the bike. It could also be that you are holding on too tightly. I'd ask a shop to look at the bike, and you could also see if anybody around has some bike handling classes. My guess is that it's more you than the bike because of your description of nervousness.

There are some drills you can try here:

https://active.com/story.cfm?story_id=12675

Let us try to help each other. I do relate to your post but perhaps for different reasons. Let me be specific. Arizona. Going down from Mingus mountain. We had bikers in our group going at 50 MPH.
I chicken out at 35 MPH. WHY? My sense of risk was telling me that I was jeopardizing my life. The other guys and girls had no such fear. My mind said this: How can I go down this road (of which I know nothing of) and risk my life and my family well being for exactly what? End of story.

Thanks for the input all. No it's not a joke, I wish it were! I did check the front hub and discovered virtually no grease and one of the cones was badly grooved. I have not pulled the headset apart yet to look at it. Thanks again, peon402.

You haven't said anything for a while. I hope that means that you have resolved the problem. Did the mechanical checking and repairing resolve this for you?

If it isn't a mechanical problem try just resting your hands on the bars. At most just kind of hook your fingers around the hoods or bar without gripping.

How fast are you going when the problem occurs?