- Published: Monday, 20 October 2014 15:16
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Figure 1. The Vision electric bicycle—monocoque carbon fiber frame, mid-drive motor, controlled with your smart phone
Purists abhor the idea of putting motors in their bicycles—they say it destroys the very idea that the bicycle represents. Athletes of course need their workout—the harder they have to pedal, the better for their bodies. Environmentalists regard all motorized vehicles to be anathema, and putting a motor in a bicycle is the antithesis of pedal power. Yet, the goal to get more people on bicycles may necessitate advocates embracing the idea of motorized bicycles, or at least bicycles that use electric motors to assist the cyclist.
The trend towards electric bicycles appears unassailable. The big bike manufacturers—Giant, Trek, Cannondale—have seen the light and are producing their respective versions of e-bikes.
Figure 2. Trek e-bike with rear hub motor
Figure 3. Giant e-bike with rear hub motor
Figure 4.Cannondale e-bikes with mid-drive motors
The e-bikes of the 80s were generally regular bicycles that were converted to electric drive by the replacement of either the front or rear hub with one that had an electric motor built in. The motors generally came from China, which even then already had a huge e-bike industry. The typical China e-bike, however, looked like a mini-scooter with the only reference to a bicycle being the pedals.
Figure 5. Typical China ebike with rear hub drive
Technologically more advanced e-bikes are in-demand in Europe. So much so that motorcycle companies such Yamaha and KTM have sought a slice of the market. Yamaha has developed a system kit composed of a crank mounted electric drive motor and its associated controller, battery, and display. It has partnered with Taiwan’s Giant bicycles to build e-bikes to be equipped with such a drive system.
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KTM, which produces both motorcycles and bicycles for the European market, has city commuters as well as mountain bikes equipped with either hub or mid-drive motors.
Figure 6. KTM Macina Lycan 27" wheeled mountain e-bike
Figure 7. KTM e-style
While it is possible to produce an e-bike with a high-powered motor, many countries limit e-bikes to about 25 miles per hour (40 kilometers per hour); otherwise, they have to be registered as regular motorized vehicles and can be driven only with a license. That is average speed in a professional bicycle race but one that ordinary cyclists are hard to keep up for long so having motor assist can be a real benefit for commuting. It is also a boon for people who ride hilly routes or who want to tackle mountains on weekend rides but have found it very difficult just with leg power. E-bikes also benefit commuters who have to ride in hot and humid weather in which pedaling even a few meters brings a torrent of sweat in high summer. Folding bike manufacturers are already offering electric motor assisted models.
Figure 8. Dahon Ikon with front hub motor
As e-bikes become better (less bulk and weight), they are bound to attract more users who need the motor assist to get around. They show the promise of making bicycling a fun experience for more people, and that can only be a good thing.