An eZee Cadence Electric Bike
Believe it or not, electric bikes have been around for over 100 years. Attaching an electric motor to a bicycle has always been a fascination for engineers looking to improve upon the basic two-wheeled design. Until recent years, electric bikes were bulky, problematic, and inefficient. It wasn’t until the 1990′s when electric bikes could run for more than 10 miles on a single battery charge. Once this was possible, the market exploded. With rapid advancement in battery technology, there are some electric bikes that can power a rider for 40 or 50 miles on a single charge, and it’s improving every year. In countries like China, India, and the Netherlands, electric bikes are widely popular, selling one million models every year. In the U.S., people are just starting to catch on to electric bikes, and the number of bike sales have doubled each of the past few years. What is it about the development of electric bikes that caused this sudden surge in popularity?
Making the Electric Bike Practical
A big step in the popularity of the electric bike is the extended range of the battery. Before 2000, most electric bikes were using Sealed Lead Acid (SLA) batteries. Although these batteries were powerful enough to drive a large bike with a rider, they didn’t last very long. People could ride for about five to ten miles before they had to plug the bike in to charge. Additionally, these batteries were very heavy. Electric bikes using SLA batteries often weighed over 75 lbs. They were impractical for long trips, and stairs were out of the question. There needed to be a lighter, more efficient alternative with better batteries.
The dawn of the Lithium battery age pumped life back into the electric bike industry. These lightweight batteries shaved 20 pounds off of an electric bike, bringing the average weight down to about 55 lbs. Although still not as light as a standard bicycle, it was now easier to manage than the ridiculous SLA bikes. The range was also improved immensely. Lithium batteries run for 15 to 20 miles on a single battery charge, which is over three times the capacity of the SLA batteries. With this kind of range, it was now easy to ride an electric bike to work, school, or run errands without running the battery down all the way. New electric bikes even have the option to charge the battery while pedaling or braking, which can extend the range by 10-20 miles. As technology advances, these batteries will keep improving. It’s not inconceivable that we’ll see a Lithium battery with a 70 mile range in the near future.
Powering an Electric Bike
BionX Electric Hub motor
Motors have been around since the dawn of electricity, and a simple chain between a motor and a bike wheel would be the most effective way to power a bike for the first 80 years of development. Of course, there were many problems with these motors. The internal brushes wore out quickly, and had to be replaced very often. It also used a chain, which could stretch, slip, or rust. A motor that is protected from the elements would prove to be the most effective for everyday riders, and the development of the hub motor would help the popularity of the electric bike.
Sealed inside of the wheel, the hub motor is not subject to rust, rain, or rough riding conditions. Since most hub motors are now brushless (using electronics rather than mechanical moving parts), they are virtually maintenance-free. This type of motor has become the standard for electric bikes, and are much more efficient than the older brushed motors. Recently, some electric bikes have been developed with a bottom bracket motor, which turns the pedals, rather than the wheel. In the future, we may see motors that are completely sealed inside the bike, invisible to any onlooker.
Controlling an Electric Bike
The easiest way to power an electric bike is with a throttle. With variable speed control, the rider can set their speed manually by simply twisting the grip. This type of speed control is easy to use, but tends to drain the battery quickly. More efficient systems have been recently developed which utilize torque-sensitive motors. This kind of technology actually measures the rider’s pedal power and gives a percentage of motor assistance. Pedal harder, the motor works more. Pedal less, and conserve the battery. It’s the most efficient way to use an electric bike, and because it requires pedaling, the electric hybrid bike still feels like a standard bike.
In the past ten years alone, these improvements have helped the electric bike to become a prominent commuter vehicle. In China, there are three times as many electric bikes as cars, and many other countries are following their lead. If America can let go of their big-car mentality, perhaps we’ll see a more bike-friendly future where electric bikes are the primary vehicles, rather than cars.
All of the new technologies mentioned above are available for purchase on these electric bikes
