Crellin was a popular competitor in many sports with a long career in motorcycle racing especially at the Isle of Man TT races, mountain climbing (three Everest attempts, Kilimanjaro 2001, Aconcagua 2009), and running.
Isle of Man TT organisers released the following statement after the fatal accident:
The organisers of the Isle of Man TT Races, ACU Events Ltd, regret to announce that John Crellin has died following an incident at the 27th Milestone at the entry to the Mountain Mile during today's (Friday) Senior TT race. John, 55, was an experienced TT competitor who has competed in a number of TT races and Manx Grand Prix events. He was a civil engineer with the Department of Transport's Design Services division. The Coroner of Inquests has been informed and an investigation into the circumstances of the accident is under way.