Born in 1947 at Hazlewood Castle in the English county of Yorkshire, Harbin grew up in Swillington Common, before emigrating with his parents to Australia at the age of ten, settling in Queensland. As a child he played rugby league and was a boxer. After leaving school he completed a teaching degree.
Coaching career
Rugby league
Harbin returned to England to coach in rugby league in the late 1990s. He was appointed head coach of Wakefield Trinity Wildcats in November 2000. The club had financial problems and were expected to struggle. Wakefield Trinity Wildcats' final game of the 2001 season was a relegation battle with Salford City Reds and Wakefield Trinity Wildcats won, condemning Huddersfield Giants to the drop. However, he left the club at the end of 2001. After a brief spell as Chief Executive Officer at Dewsbury Rams, Harbin joined Oldham as head coach in January 2002.
Association football
Late in 2002 Harbin joined Oldham Athletic as fitness conditioner and sports psychologist alongside then-assistant manager Iain Dowie. Dowie was later promoted to manager and moved to Crystal Palace, with Harbin following. Dowie moved to Charlton Athletic in 2006, and again appointed Harbin to his coaching staff. After Dowie's sacking in November 2006, Harbin stayed briefly under new manager Les Reed, but departed by the end of 2006. In February 2007 he linked up with Dowie for the fourth time, at Coventry City. Striker Leon Best said that after Harbin's fitness sessions he felt he was "definitely the fittest I have ever been". A year later he was placed in a joint-caretaker's role alongside first-team coach Frankie Bunn after the sacking of Dowie. Harbin again followed Iain Dowie to Queens Park Rangers and remained following Dowie's departure in October 2008. Harbin stayed at Loftus Road under new manager Paulo Sousa until Sousa left the club in the summer of 2009. Harbin would later follow Sousa to Swansea City in July 2009.
After seven years in English Football and only three months at Swansea, Harbin decided to return to Australia to take up a senior coaching role at Yeppoon Rugby League club in the Queensland Rugby League Central Division. He was appointed as head coach of the Central Queensland Capras in September 2011. Harbin later became the manager of the Dreamtime Lodge motel in Rockhampton.