BIKER Brian Jones was fined after police stopped him for having the nickname Sooty as his registration number.
Police took the 46-year-old to court for having the "wrong shape" registration plate on the back of his Honda 600cc Hornet.
Mr Jones, known as Sooty by fellow bike enthusiasts, denied that the plate was illegal.
But he was convicted at Flintshire magistrates' court at Mold in North Wales.
Now the Wirral man claims he is the victim of a vendetta against motorcyclists by North Wales police.
The prosecution said that Mr Jones' registration number - S50 OTY - should be on a square plate written on two lines.
But as he entered North Wales on the Cheshire border at Sealand in May a police officer saw that it was all on one line to spell out the nickname.
Mr Jones said he had travelled all over the UK with the number plate and had never been stopped before.
Mr Jones, a mechanical scrutineer for motorbike racing authority the Auto Cycle Union and a former amateur racer himself, said that the size and spacing of the letters were correct and lawful.
But magistrates disagreed and fined him £30. He was also ordered to pay £50 costs.
Mr Jones, from Thingwall, said he was disappointed to be convicted and would take legal advice over an appeal.
