Belt-driven bicycle with a compact design that, like STRiDA, featured a belt drive. Other folding-bike manufacturers that have implemented a belt drive include U.S. company Bike Friday and Netherlands-based Bernds. In 2007, Gates Corporation developed a high-modulus synchronous belt and sprocket system called the Carbon Drive System. The belt’s pitch allowed for lower tension requirements to help prevent skipping. Lightweight, patent-pending sprockets have mud ports, openings under each tooth, which work to slough off debris. In 2009, an increasing number of bicycle companies, including Trek and "f"8 Cycles, offered belt-driven bicycles. While builders initially focused on single-speeds and internal hubs, in early
Butterfly Trek Madone Butterfly Trek Madone The Butterfly Trek Madone, an artwork utilizing a bicycle by Damien Hirst, became the world's most expensive bicycle when it was bought at auction for $500,000. It was designed by Hirst, who used real butterfly wings that were placed onto the actual frame and rims of the bicycle. The bike had been ridden by Lance Armstrong in the 2009 Tour de France. The "Butterfly Trek Madone" currently holds the title of the most expensive bike sold in the world. The second most expensive bike ever sold was the Trek Yoshitomo Nara Speed Concept that was sold for