Makers Intelligent Energy of Britain contracted with Seymourpowell to design a zero-emission hybrid bike, and design they did. Only trouble is, the bike is quiet. Too quiet — the Emissions Neutral Vehicle produces an amount of noise equivalent to that of a PC fan belt, which clearly won’t cut the Harley mustard, besides being potentially deadly to pedestrians. The designers are now looking into ways to introduce some artificial vroom into the bike, which has no gears and can reach tops speeds of about 50 miles per hour. The motorcycle is powered by a hydrogen fuel cell the size of a briefcase, and needs refueling about every 100 miles — which had better be round trip, as there’s currently only one station in all of Britain that supplies it.