When the flag drops, the bullsh*t stops, as they say in racing, and few sectors in the auto market have as much to prove as electric motorcycles. The performance potential of electric bikes is almost unbounded, with massive advantages over petrol bikes in so many areas - and battery technology is starting to catch up with the market's needs - but until recently, there's been no international competitive showcase for the top level of electric motorcycles. Just this week, the FIM announced a zero-emissions TT Grand Prix on the Isle of Man in June - and paved the way for electric bikes to compete in the future against top-level petrol bikes. Now, off-road specialists Zero Motorcycles are gearing up for the world's first all-electric 24-hour endurance motocross race in California on April 4. The flag has dropped on electric racing. Time to see who's got the goods, and who's been telling porkies.