A belt-driven bicycle is a chainless bicycle that uses a toothed synchronous belt to transmit power from the pedals to the wheel. The belts are typically made by the same manufacturing companies that produce timing belts for automobiles, machineries, and other synchronous belt drive applications.
The application of belt drives to bicycles is growing, especially in the commuter bicycle market, due to the low maintenance and lubrication-free benefits.
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The Bridgestone Picnica belt-drive bicycle was introduced in the early 1980s. It used a tooth-belt drive like auto timing belts and Harley-Davidson drive belts, along with a novel two-part chainring that increased belt tension with increasing load. The Picnica was a folding bicycle, and part of the appeal of the belt drive was cleanliness. The Picnica was a small wheel bicycle, so belt tension may have been less than on a bicycle with standard-size wheels. It was apparently successful, but was offered mainly in Japan.
Bridgestone did offer belt drive bicycles in the USA until they left the market about 1994. Since their innovation, they have continuously offered belt drive bicycles in Japan including their best selling Albelt model.
In 1984 and 1985, Mark Sanders, a designer who had earned his degree in Mechanical Engineering from Imperial College, London, designed a folding bicycle as part of his graduate studies in an Industrial Design Engineering (IDE) program. The program was run jointly by Imperial College and the Royal College of Art in London. He collaborated with a design engineer from Gates Corporation to outfit his bicycle with a belt, rather than a chain.
When his project was complete, Sanders chose entrepreneur and former Greg Norman manager James Marshall and a Glasgow manufacturer to turn his award-winning design into a product. The manufacturer coined the name STRiDA, and in 1987 the bicycle began rolling off the production line. In 2002 production was moved to Taiwanese manufacturer Ming Cycle in order to meet increased demand, and as of 2007, Ming Cycle fully owned the STRiDA brand and intellectual property rights.
iXi bicycles, distributed in the United States by Delta Cycle Corporation, followed in 2004 with a compact design that, like STRiDA, featured a belt drive.
Possibilities for belt-driven bicycles have widened as hub gears inside the rear hub, were applied. In lieu of a derailleur, the hub gear allows riders of belt-driven bicycles to shift easily. Major internal hub makers include Shimano (Nexus), SRAM, Sturmey-Archer, Fallbrook Technologies's NuVinci and Rohloff.
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. Early adopters who helped evaluate, revise and introduce this system included Frank Scurlock of Spot Brand Bicycles and Kalle Nicolai of Nicolai Ltd.
In 2009 an increasing number of bicycle companies, including Trek and f8 Cycles, offer belt-driven bicycles. While builders initially focused on single-speeds and internal hubs, in early 2009 f8 used a Gates-compatible fixed gear cog designed by Phil Wood & Co.[3], offering a belt-driven fixed gear bicycle.
Notable manufacturers of belt-driven bicycles or belt drives include: