Tilo Niebel and his co-pilot, Wilfred Niebel, ride the world's heaviest motorcycle onto a scale in Zilly, a town in Germany's Harz Mountain region. Officials from Guinness World Records were on hand to certify the bad bike as the world's heaviest -- it weighed in at 4,740 kilograms (10,450 pounds). Tilo Niebel built the motorcycle and side car around an 800 horsepower engine from a Russian T55 tank.