To those who are still convinced that loud motorcycles make you more safe: it's best you look away now. The quietest bikes in the business just got even more silent. Zero Motorcycles just has unveiled its 2011 lineup of electric motorcycles and among a suite of generally tidy enhancements comes a change to belt drive. This means no more chains, no more chain lube, and no more rattling and grating noises. There's nothing but the sound of the wind and the faint scream of the motor, which you can hear for yourself in the video below. Also new is a 12.5 percent boost in battery capacity and a quick-charge option that drops charging times in half -- but does so at an up-front c
