The use of electric bicycles as an alternative means of transportation dates back as far the 1890’s believe it or not, beginning with rudimentary DC motors mounted on rear hubs. Today, it is estimated that between 10 and 20% of all bicycles used in many major cities involve some form of electric assist, and are collectively referred to as e-bikes. Major advances in motor and battery technology, and thus range, have paved the way for the recent surge in popularity.
At Optibike, we design and manufacture the best electric bicycles on the market with an emphasis on long-range capabilities. So, exactly what goes into determining the range limits of different e-bikes. We’d like to share some information with you we think will be both educational and aid in your electric bike purchasing decisions.When we speak of “range”, we are collectively referring to how far an electric bicycle will travel in miles before the battery loses it charge. Because they vary in the nature of how they are assisted, our focus will be on bikes propelled by motor and battery alone. You see, some rely on pedal input from the rider to extend their range. So, among truly electric bicycles, range is determined primarily by a combination of 6 factors:
The speed the rider is traveling
The steepness of the terrain
The weight of the rider
The combined aerodynamic drag of the rider and bike
The efficiency of the motor drive system
The energy of the battery (measured in watt-hours or Wh)
For purposes of brevity, we will limit our discussion to two factors we take great pride in; Optibike’s cutting-edge technology in battery and motor drive innovation. Because, if 2 bikes and riders have factors 1 through 4 being identical, then range is solely a function of factors 5 and 6: the watt-hour energy capacity of the battery and efficiency of the motor drive system.
Simply put, the watt-hour capacity of the battery determines how far you can travel before recharging. Batteries are rated in either amp-hours or Watt hours (Wh). Total energy output is given in Watt hours (Wh) and is a product of the volts times the amp-hours. For example, a 37-volt battery with 10 amp-hours has capacity of 372 watt hrs. This means the battery can put out 372 watts for one hour.
For long range touring purposes, Optibike pioneered the use of Lithium Ion batteries, with the largest energy capacity of any electric bike. Depending on mode and speed, our 48-volt battery produces between 385 & 1100 Watts of power with a range between 22 and 45 miles, while traveling at high speeds. Optional touring batteries can extend range up to 90, even 100 miles.
The efficiency of the motor drive system is also integral to electric bike range, all other factors considered equal. An e-bike can be thought of as a motorized bike, a motor drive does transfer power from the battery to the wheels propelling you forward. Optibike revolutionized motor drives with the introduction of its patented Motorized Bottom BracketTM (MBB) system, extending electric bike range. The MBB has the highest power to volume ratio of any drive system, and is combined with a patented Derivative Power ControlTM (DPC) system. DPC allows you to have both high acceleration and high efficiency, further extending your range over other electric bikes.
In summary, today’s high energy density, powerful and lightweight Lithium Ion batteries, when paired with innovative motor drive systems, have resulted in extending the range of electric bicycles to previously unseen limits.
Want to learn even more? Jim Turner, President at Optibike, has authored an informative and entertaining look at the rapidly expanding world of electric bicycles. Get your free copy of the eBook today and follow our weekly blog to get more tips and resources from The Electric Bike Book. Next week, we’ll discuss what to look for when buying an electric bike.