There’s a reason why Jay Leno is crazy about pre-war motorbikes: so few survive from the period that those that do exist are highly prized and hugely collectable. In April 2014 the highest price ever achieved for a 1930s Brough Superior SS100 was reached at the Bonhams annual vintage motorcycle sale: £253,500, almost double its estimate. In April 2015, an even rarer machine will go under the hammer: the beautiful 1939 Vincent-HRD 998cc Series-A Rapide. This one, says Bonhams motorcycle expert Ben Walker, is “in concours condition, and one of those models that collectors and enthusiasts dream of: owned by one family since 1959, and the second-last ever to be produced”. Not all motorcycles are quite as good investments, according to Tennessee vintage bike broker Somer Hooker. “Buying a bike is like buying art,” he warns. “It’s worth buying something you like because you may have to live with it. People get tired of paper assets. It’s more fun to go out in the garage, see what you’ve got and take it for a ride.”