I'm pretty sure this may have been covered at least once so humor an old phart. Coming home from work I slowed down for a red light and momentarily took my hands off the bars. Within a split second the front end/wheel started to shimmy a bit. Nothing dramatic but I didn't know if it would get worse so I grabbed the bars. Jacked it up today and checked for looseness on wheel. Nope. Took handlebars and shook for steering looseness. None. Wheel isn't out of round in any way as I put a homemade gauge on it. The only possibilities left are the wheel needs re-balancing, I hit a spot in the pavement coinciding with my hands off that threw it off balance or I got a gremlin for which I bought a "Heroes" bell. I'll have to try and repeat the scenario when the rain clears area (next week).

Greyphart

PS Found another link and read that. Checked air pressure it's good to go @ 40.