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.