Sebastian,
I used to have the same symptoms that you speak of. But I found out what was going on. Here is what happened, - one of the ears on the "drive ring" (for the Speedometer Drive) broke off, and the speedometer was being driven by the other ear. Finally, it broke off too. When the first one broke off, that little piece of metal lodged in the bearing. You see, some time ago I discerned a new & minute vibration as I gripped the handlebars. So I disassembled the Speedometer driving system on the front wheel and tapped both bearings out. One of the bearing was very rough feeling, while the other was smooth as silk. Without doubt, my weird vibration was caused by that rough feeling bearing. Anyway, I ordered two new bearings from "Gerrish Bearings" (website =
http://www.usabearing.com/ ).
One of the thing to look for is this, does the indicator needle on your speedometer vibrate when showing your speed" If "yes," then it is probably being driven by only one ear on the drive ring (and the other ear is now a fragment of metal that is wreaking havoc with your bearing).
Anyway, I'm excited to get back the smooth riding motorcycle I had before.
-BT
