I was going down a long descent yesterday on my LHT. I was riding with no hands for maybe a half a mile or so, and my front wheel and bars stated to wobble rapidly. when I grabbed the bars it stopped. I let go again to see if it would do it again and it did. I kept my hands hovering over the bars at about an inch to see if it would get any worse and it didn't, really. Maybe if I had let it go longer, but I was getting a bit worried about crashing.
Is this normal? I didn't really feel like it should have been doing that. Maybe I'm wrong. I tried searching the forums for this, and I didn't find too much that was quite similar to this experience.