Beschreibung
Jefferies competed in a range of racing classes including the Isle of Man TT. In 2002, Jefferies set the absolute lap record for the Isle of Man TT course.
He was killed in 2003 while racing a Suzuki GSX-R1000 for the newly formed TAS Suzuki team at the Isle of Man. Jefferies died during practice for the Senior TT after hitting oil on the course from a competitor's malfunctioning bike. Track marshals failed to provide adequate warning, namely by failing to wave an oil flag, for the approaching Jefferies and Jim Moodie. He crashed at Crosby at approximately 160mph (257 km/h). Moodie was seriously injured but survived. The parade lap in honour of Jefferies took place at the end of the TT weekend where thousands of bikes took part, filling the 37 mile course.