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
Trek Bicycle Corporation a few years Trek had outgrown its original "red barn" manufacturing facility—a former carpet warehouse. Recognizing the need for expansion, in 1980 Trek broke ground on a new corporate headquarters on the outskirts of Waterloo. Company co-founder Dick Burke would later recall that "it wasn’t until we built the new factory that we became a business." With more factory space available, Trek expanded its manufacturing to include complete bikes. In 1981 Trek entered the steel road racing bike market, introducing the "Pro" line, including the 750 and 950 models, and in 1983 Trek built its first mountain bike, the 850.