I noticed recently that there is some kind of wobble in the front end of my bike. It's really only apparent when I'm going very slow such as creeping in traffic, and usually with the clutch in. The handlebars twitch rhythmically in time with wheel rotation but it's a small enough movement that speed or engine vibration largely mask it.
The first thing that came to mind was a warped rotor. However braking doesn't seem to affect the wobble one way or the other, which would suggest to me that the rotor isn't the problem.
Any ideas what about what is causing it?