The giant fan, known as ThrustPac, can blow bikers along the roads at up to 35mph, enabling them to keep pace with traffic. Comprising an engine and propellor, and weighing 9kg, the kit is fixed to a shoulder harness. A special glove controls the device; cyclists bend their fingers to accelerate the fan and relax them to slow it down. The US gadget costs from £455-£1,000.