Watts Up With E-Bikes


By Randy Archer

Like so many others, there you are thinking about joining the growing community of e-bike riders. But where to start? First things first, you need to consider what kind of bike you need. And the variety of market segments to choose between, this is actually the easy part. Be it a mountain bike, a commuter bike, a road bike or a cargo bike, there is undoubtedly an e-bike out there that will be suited for your recreational/transportation needs.

Now comes the harder part—you know, the actual electric part! Confused by all the specs? If you’re trying to sort it all out, don’t worry, you’re not alone. It is difficult to understand. Lots of folks are asking about the various specifications and classifications. The goal of this article is to help you sort through a few of the most often-asked questions and takes a stab at making it easy to understand.


In many states and jurisdictions, e-bikes are classified into three types, and most manufacturers follow this grading. Basically, the breakdown is as follows:

• Class 1 e-bikes only help you pedal up to 20 mph. After 20 mph, you are on your own. There is no throttle. 

• Class 2 e-bikes also help you pedal up to 20 mph, but you get a throttle, too.

• Class 3 e-bikes help you pedal up to 28 mph and may have a throttle option, but the throttle is usually limited to 20 mph. 

Although every manufacturer wants to stand out and tout what’s special about their bike, some specifications do help you sort out what is important to you. The following will help you sort and compare brands and models.


This is easily the most common specification compared by buyers. Morning jolt or decaf, more is usually better. But higher octane comes at a higher price. Think of volts as the push or force provided by the battery. 24, 36, and 48 volts are the most common. 12 volts is best kept to scooters and toys. Higher-voltage systems are better at getting the power from the battery to the motor. It’s because wire has resistance and volts are lost as they travel to the motor as heat. The closer the motor is to the battery, the better, at least, for controlling voltage drop.


Resistance is, as the name implies, the difficulty made by the electric circuit to get to the load, where the real resistance—the motor—does the work. Not to be confused with my 20-year-old’s reluctance to do chores, but nonetheless, similar in result, the work doesn’t get done. The greater the distance the battery is from the motor, the bigger the wire needs to be to avoid the voltage being reduced, and the less current makes it to the motor. 


 Amperage is more like the current in a river. Electrons flow and transfer energy along a wire circuit. Higher voltages push more current, which results…