83 years with the same motorcycle (a Quadrant with a Minerva engine)... that might be a record. Percy Pritchard

above, in 1903, below, he is age 90 in 1986

Found on http://www.oldbike.eu/museum/bikes-1800s/1869-1891-velocipedes-dwarf-safeties/1889-harry-s-roberts-special-gents-safety-bicycle/