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
Specialized Stumpjumper in full (front and rear) suspension and hardtail (front suspension only) options, with the former named the Stumpjumper FSR. Professional mountain bikers who ride Stumpjumpers include Christoph Sauser and Ned Overend. Overend won the 1990 Mountain Bike World Championships – the first ever event of its kind – on a carbon-fiber prototype Stumpjumper. Specialized Stumpjumper The Specialized Stumpjumper is a mountain bike produced by Specialized Bicycle Components. When it was first produced in 1981, the Stumpjumper was the first mass-production mountain bike. The Stumpjumper is still in production, although its design has changed significantly since it was first sold. Stumpjumpers