Jack Robinson

I've had my Rocket 3R since new. Up to about 17,000km it ran very smoothly across the whole rev range. For the last 3,000km a very high frequency vibration has developed felt through the handle bars foot pegs and seat. Worst from 4000 revs however easily felt at all revs. It's the same when the motor is revved while stationary. The first 17,000km was so smooth! Has anyone had a similar experience?