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.

Motorcycle manufacturer KTM has long produced bicycles too, but it is in the e-MTB category that the brand’s heritage is really employed. Motocross fans and riders looking to get into e-MTB riding will appreciate KTM’s decision to use a ‘precise’ 29er front wheel and ‘traction rich’ 27.5-Plus rear wheel (MX bikes also feature different front/rear wheel sizing), an approach some other manufacturers have also adopted (e.g. Canyon). The bike is adorned with a solid build kit including e-MTB-specific parts like SRAM’s EX1 drivetrain.
The environmental effects involved in recharging the batteries can of course be reduced. The small size of the battery pack on an e-bike, relative to the larger pack used in an electric car, makes them very good candidates for charging via solar power or other renewable energy resources. Sanyo capitalized on this benefit when it set up "solar parking lots", in which e-bike riders can charge their vehicles while parked under photovoltaic panels.[66]
It means you can fit much more riding into one session. Or if you want to cover more distance (as often the best riding spots are quite far apart here in the UK) e mountain bikes are perfect for the job. All the usual MTB configurations are available – everything from wheel size to forks and more, and there’s the choice of hardtail or full suspension electric mountain bike too.
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.[9] 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.
E-bikes use rechargeable batteries and the lighter ones can travel up to 25 to 32 km/h (16 to 20 mph), depending on local laws, while the more high-powered varieties can often do in excess of 45 km/h (28 mph). In some markets, such as Germany as of 2013, they are gaining in popularity and taking some market share away from conventional bicycles,[1] while in others, such as China as of 2010, they are replacing fossil fuel-powered mopeds and small motorcycles.[2][3]