I have removed the bearings and spindle..The spindle feels good..no apparent ridges. The bearings look ok to be honest..lots grease and lube about them.Not sure why they seem to be vibrating other than previously mentioned, that they might need adjusting. So i will replace the two ball bearings, and see what transpires..
Q/ if the back gear lever was in back gear position when the motor is running at high speed. What would the outcome be...poor finish and knocking ?