SUPER GUIDE TO
HERE’S A PUB GAME FOR YOU: WHAT IS THE most important postwar British motorcycle? The Vincent Black Shadow? The Triumph Bonneville? The Featherbedframed Manx Norton? The BSA Gold Star? If the question was ‘greatest’, then one of these would surely be at the top of the list. But for ‘most important’? The motorcycle that got the world – or at the very least, the British Empire and Commonwealth – moving, that provided transport for teenage tearaways and the solid, stolid working stiff, that helped farm the Australian outback, and without which the wheels of industry and high finance would have stumbled and functioned irregularly? The one that, almost overlooked, kept Britain’s biggest motorcycle manufacturer going, had 23 years in production, half a million produced, and ensured that the phrase ‘one in four is BSA’ was more than just advertising hyperbole, but genuine and accurate.
I give you the BSA Bantam. The most important postwar motorcycle Britain ever made. And it wasn’t British, originally.
Truly successful motorcycle manufacturers know that to remain successful, it’s the little things that count. Just ask Honda. A good, small-capacity, mass-market motorcycle is vital as the basis of the range. It must be robust and reliable, and ready to work every day.
The two-stroke single was the starting point for many before the Second World War, but British manufacturers had a problem. The best engine was one built by DKW in Germany – and it held the patents. DKW didn’t design the engine, however. That was another German engineer called Adolf Schnuerle, in 1924, at the age of 28.
Normal two-stroke engines had an inlet port at the back, an exhaust at the front, and to maintain the right kind of gas flow, used what is known as cross scavenging. This is where the flow will pass from the inlet directly to the exhaust, with a domed piston to direct the gas flow upwards, flow around the combustion chamber then down through the exhaust port. Schnuerle’s design used ports on the same side of the cylinder, with the
