An award-winning restorer of classic motorcycles, Derek Wilkinson, who has died peacefully aged 69 after a long illness, helped to build and design many of the Lotus prototypes.

He joined Colin Chapman as an apprentice in 1968 shortly after Lotus had moved to Hethel, and in his early years was a member of the highly-successful Formula One racing team.

Born at Barnham Broom, near Norwich, Derek John Wilkinson started work in agricultural engineering before joining Lotus. When he retired in 2006, he was one of its longest-serving employees. As part of the development team in hot and cold testing of prototypes, he later travelled the world.

His first love was always motorcycles and over the years, he won many prizes at some of the country's biggest classic events. One project, the complete restoration and re-building of a 1962 Honda Benly from a frame and two wheels took seven years as he had to source parts for this rarest bike from all corners of the world. It won a national award.

He also took best-in-show at Thetford, Copdock, Ipswich, and first prizes at the Wimbotsham Fenman classic bike show. Only this year, he reached the last 10 in his group for a national built-in-Britain competition. It is likely that two of his restored motorcycles may be acquired for permanent display in museums.

He leaves a widow, Ann, known as Berrie, and daughter, Nicola and son, Christopher, stepchildren Helen and Alan, and six grandchildren.

A funeral service will be held at Wymondham Abbey on Thursday, November 29.