E-bike products and scooters Cycling Without that Pesky Peddling - Page 9

Wheels and Brakes The wheels used in electric cycles are not the same as a standard wheel used in a tradition bicycle. This is because if you are powering the wheel using a motorized hub the spokes will need to be stronger to prevent them buckling under the higher torque – the turning force -supplied by the motor. To support this higher drive torque requires that the wheel – whether the front or back – being motorized will need special reinforced spokes and a different configuration, i.E. Bigger, thicker, and fewer spokes. The brakes also differ from a standard bicycle as they too have to deal with not only the additional torque from the motor but also the higher speeds. Some electric bicycles claimed to use a technique called regenerative braking which is highly effective in electric trains and cars. The principle behind regenerative braking is that starting say an electric car for example requires a huge amount of energy to overcome inertia and get the vehicle moving however that energy is then wasted when you have to brake as it is dissipated as heat through the brake pads. The idea is that it would be good if we could store that energy rather than waste it so we could reuse it later and that is the concept of the regenerative brake. The way it works is that all the kinetic energy that would have been wasted as heat loss through the brake pads can now be used to recharge the battery. In addition during periods of downhill travel when the wheels are rotating faster that the motor this additional kinetic energy can also be harvested to recharge the battery. This is a solid and proven technology in electric trains and cars but it unfortunately seems to be less effective in electric bicycles as they have far less mass and so far less energy loss when braking.