However, the bike is still eligible for racing with the 'Uprights', a broadly classic type category of bikes that are around 20 and more years-old. Unfortunately, mixed in with the 350 and 500cc bikes, Tim was giving away a lot of horsepower.
Graham Field helps Tim with bike preparation. Graham's skills came from preparing and riding dirt track Douglas models for tuner Len Cole. Tim and Graham decided to try and improve the C15, but soon discovered 350cc B40 barrels were rare and thus expensive. Eventually, the original barrel was bored out as far as it was deemed safe, leaving a bore big enough to fit a 71mm piston from a Triumph twin. The actual capacity is now 277cc.
But does it work? Riding in tricky conditions at an Easter grass track in Grafty Green, Kent, Tim was on the only bike of less than 500cc to qualify for the final – and he was not last in that race.Enjoy more The Classic MotorCycle reading in the monthly magazine. Click here to subscribe.