Vibration

[Davew]

I think I've found the culprit.  I've had the bike stood and revved it to the vibration point, and theres nothing coming from the engine at all.  It's where the downpipes merge under the bike where I've patched a couple of small holes.  It seems to be coming from there and travelling up.
I'm going to be getting stainless downpipes soon, so hopefully that may solve the problem.  I'm guessing its just the resonance of the old pipes thats causing it.