China has experienced an explosive growth of sales of non-assisted e-bikes including scooter type, with annual sales jumping from 56,000 units in 1998 to over 21 million in 2008, and reaching an estimated fleet of 120 million e-bikes in early 2010. This boom was triggered by Chinese local governments' efforts to restrict motorcycles in city centers to avoid traffic disruption and accidents. By late 2009 motorcycles are banned or restricted in over ninety major Chinese cities. Users began replacing traditional bicycles and motorcycles and e-bike became an alternative to commuting by car. Nevertheless, road safety concerns continue as around 2,500 e-bike related deaths were registered in 2007. By late 2009 ten cities had also banned or imposed restrictions on e-bikes on the same grounds as motorcycles. Among these cities were Guangzhou, Shenzhen, Changsha, Foshan, Changzhou, and Dongguang.
Added help on the hills: An extra boost on the hills or when cycling into a headwind is probably the first thing most people think about when they’re considering an electric bike. If you live in a valley where the only way out is up, then having a bit of motor assistance may mean the difference between a happy cycling experience and not cycling at all.
Battery-electric locomotive Battery electric vehicle Cater MetroTrolley Electric aircraft Electric bicycle Pedelec Electric boat Electric bus Battery electric bus Electric car Electric truck Electric platform truck Electric vehicle Electric motorcycles and scooters Electric kick scooter Gyro flywheel locomotive Hybrid electric vehicle Hybrid train Motorized bicycle Neighborhood Electric Vehicle Plug-in electric vehicle Plug-in hybrid electric vehicle Solar vehicle Solar car Solar bus
Out on the road the Soho is easy to fire up, just press the button hidden under the top tube (a nice discreet touch), you’ll then get a set of five top-tube mounted LED’s light up to give you a charge indication. First impressions were that the engagement of the motor is a little jerky in tight traffic (tested in central London) and you could find yourself pulled toward the cars you’re weaving though at slow speeds - unless you’re feathering the brakes.
Controllers for brushless motors: E-bikes require high initial torque and therefore models that use brushless motors typically have Hall sensor commutation for speed and angle measurement. An electronic controller provides assistance as a function of the sensor inputs, the vehicle speed and the required force. The controllers generally allow input by means of potentiometer or Hall Effect twist grip (or thumb-operated lever throttle), closed-loop speed control for precise speed regulation, protection logic for over-voltage, over-current and thermal protection. Bikes with a pedal assist function typically have a disc on the crank shaft featuring a ring of magnets coupled with a Hall sensor giving rise to a series of pulses, the frequency of which is proportional to pedaling speed. The controller uses pulse width modulation to regulate the power to the motor. Sometimes support is provided for regenerative braking but infrequent braking and the low mass of bicycles limits recovered energy. An implementation is described in an application note for a 200 W, 24 V Brushless DC (BLDC) motor.
Electric bikes are here in a big way. Liberated from some of the normal constraints of standard bike design like weight and gearing, e-bike design has exploded; if you can imagine it, someone has built it. From cargo bikes to city bikes, messenger bikes to mountain bikes, road bikes, and even beach cruisers, there is something for everyone. The beauty of e-bikes is they make the joy of cycling accessible to so many people in so many ways.