Chris Jones, from Bromsgrove, was flown by the Yorkshire Air Ambulance to Hull Royal Infirmary. The Motorcycle Circuit Racing Control Board, who organised the race, confirmed three riders were injured, with Jones' condition considered as critical.
All of the injured riders were treated first at the scene and then at the circuit medical centre by the British Superbike Championship medical team before being transferred to the nearest appropriate hospitals for their injuries by both ambulances and helicopter.
Carl-Thomas Andrews, also aged 14, from Newark, sustained a right shoulder injury and was transferred by ambulance to Lincoln Hospital.
Jon Vincent (38), from Bickerstaffe, sustained abdominal injuries and was transferred by ambulance to Grimsby Hospital.