Fruin were motorcycles produced from 1957 to 1963.
Having already been a keen supporter of 125cc road racing during the 1950s, towards the end of the decade Bert Fruin became interested in the new 50cc racing class. He then went into limited production of machines for that class, plus a similar one for sports road use.
Both machines used the Italian Demm engine, and tubular frames with conventional suspension. The motorcycles were sold as the Dart. Fruin rode one of his machines in the early 50cc TT races. Later he built a 125cc twin and was a regular contender in UK events, as well as four TT races.
There were plans for a 200cc engine to be sold in kit form. These were to be four Demm engines built up in-line, but nothing came of the idea.