Grinding noise/feeling around 6000rpm

[Fazerider]

I think Limax's opinion, that this is just the standard "rough zone" the Fazer has, is probably the correct one. The engine mass combined with the rubber mounts has a resonant frequency, and when the reciprocating parts hit that range you do feel more of a buzz though the footpegs and bars.
The solution, of course, is to spend as much time as possible above 7000rpm. :b