A weird "vibration" through the handlebars

OK - for those who dont know, not so long ago I had a slow (20mph) speed off with my red rocket3. a few things were scuffed and cracked, but for the most part the bike appeared ok. Being sensible, I had the bike looked at by my local dealer and they gave me a list of items to swap to "make good", but after speaking with them this was a case of replacing lights which were smashed, and replacing parts which were scuffed. They said the bike was fine - nothing bent.

My friends and I made the bike good from my mass of spares, and everything seemed fine - including the handling.

I had to swap the wheels/tyres from the metzlers which were on at the time of the crash and afterwards when the bike was made good, to new wheels with avons on them. these are complete wheels with discs on etc and have been used for less than 1000miles from my other rocket3 (took the avons/wheels off when I went to the darkside). Anyways - now when I ride the red rocket3, at speeds of around 20-35mph I feel a vibration through the handlebars. Whereas before I could safely take my hands off the bar (if I so desired) at that speed - now, the handlebars will start to wobble/shake albeit a small amount, it is noticable. Obviously riding with my hands on the bars is fine - I can control the little shake/wobble/vibration, but its obviously not right.

What could it be? The wheels arent balanced properly? the discs are warped? headstock bearings? slightly bent fork from the crash (but then the metz wheels would have should something wouldnt it)?

Anyone any ideas?

Low-speed wobble -- if that's what it is -- is usually a result of front tire wear (I think it's called "cupping"). My V-Max had this problem until I replaced the front tire with new (again, a Metzler).

All of the obvious tests - if you haven't done them already.

Try fully deflating tyres and re inflating with - could be tyre not beaded in rim properly.

If you can get bike off deck easy enough spin wheel to see if out of alignment - might need to ease pads back to get it to free spin

Check wheel balance.