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An electric bicycle, also known as an e-bike or booster bike, is a bicycle with an integrated electric motor which can be used for propulsion. There are a great variety of e-bikes available worldwide, from e-bikes that only have a small motor to assist the rider's pedal-power (i.e., pedelecs) to somewhat more powerful e-bikes which tend closer to moped-style functionality: all, however, retain the ability to be pedalled by the rider and are therefore not electric motorcycles. E-bikes use rechargeable batteries and the lighter varieties can travel up to , depending on the laws of the country in which they are sold, while the more high-powered varieties can often do in excess of . In some markets, such as Germany, they are gaining in popularity and taking some market share away from conventional bicycles,〔(【引用サイトリンク】url=http://www.evworld.com/news.cfm?newsid=29891 )〕 while in others, such as China, they are replacing fossil fuel-powered mopeds and small motorcycles.〔 Depending on local laws, many e-bikes (e.g., ''pedelecs'') are legally classified as bicycles rather than mopeds or motorcycles, so they are not subject to the more stringent laws regarding their certification and operation, unlike the more powerful two-wheelers which are often classed as electric motorcycles. E-bikes can also be defined separately and treated as a specific vehicle type in many areas of legal jurisdiction. E-bikes are the electric motor-powered versions of motorized bicycles, which have been around since the late 19th century. ==History== In the 1890s, electric bicycles were documented within various U.S. patents. For example, on 31 December 1895, Ogden Bolton Jr. was granted for a battery-powered bicycle with “6-pole brush-and-commutator direct current (DC) hub motor mounted in the rear wheel.” There were no gears and the motor could draw up to 100 amperes (A) from a 10-volt battery.〔http://www.google.com/patents?id=DIVIAAAAEBAJ&dq=552,271〕 Two years later, in 1897, Hosea W. Libbey of Boston invented an electric bicycle () that was propelled by a “double electric motor”. The motor was designed within the hub of the crankset axle.〔http://www.google.com/patents?id=ZiZEAAAAEBAJ&dq=596272〕 This model was later re-invented and imitated in the late 1990s by Giant Lafree e-bikes. By 1898 a rear-wheel drive electric bicycle, which used a driving belt along the outside edge of the wheel, was patented by Mathew J. Steffens. Also, the 1899 by John Schnepf depicted a rear-wheel friction “roller-wheel” style drive electric bicycle.〔http://www.google.com/patents?id=F2JHAAAAEBAJ&dq=627,066〕 Schnepf's invention was later re-examined and expanded in 1969 by G.A. Wood Jr. with his . Wood’s device used 4 fractional horsepower motors; connected through a series of gears.〔http://www.google.com/patents?id=BFhrAAAAEBAJ&dq=3,431,994〕 Torque sensors and power controls were developed in the late 1990s. For example, Takada Yutky of Japan filed a patent in 1997 for such a device. In 1992 Vector Services Limited offered and sold an e-bike dubbed Zike. The bicycle included NiCd batteries that were built into a frame member and included an 850 g permanent-magnet motor. Despite the Zike, in 1992 hardly any commercial e-bikes were available. Production grew from 1993 to 2004 by an estimated 35%. By contrast, according to Gardner, in 1995 regular bicycle production decreased from its peak 107 million units. Some of the less expensive e-bikes used bulky lead acid batteries, whereas newer models generally used NiMH, NiCd, and/or Li-ion batteries, which offered lighter, denser capacity batteries. Performance varies; however, in general there is an increase in range and speed with the latter battery types. By 2001 the terms e-bike, power bike, "pedelec", pedal-assisted, and power-assisted bicycle were commonly used to refer to e-bikes. The terms "electric motorbike" or "e-motorbike" refer to more powerful models that attain up to . In a parallel hybrid motorized bicycle, such as the aforementioned 1897 invention by Hosea W. Libbey, human and motor inputs are mechanically coupled either in the bottom bracket, the rear wheel, or the front wheel, whereas in a (mechanical) series hybrid cycle, the human and motor inputs are coupled through differential gearing. In an (electronic) series hybrid cycle, human power is converted into electricity and is fed directly into the motor and mostly additional electricity is supplied from a battery. By 2007 e-bikes were thought to make up 10 to 20 percent of all two-wheeled vehicles on the streets of many major Chinese cities.〔 A typical unit requires 8 hours to charge the battery, which provides the range of ,〔 at the speed of around 20 km/h.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Electric bicycle」の詳細全文を読む スポンサード リンク
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