Over the years, electric bikes have become one of the most popular means of transportation amongst cyclists and non-cyclists. This is because they are easy and convenient to ride.
However, convenience is not the only perk riders get from these battery-powered bicycles. They're also very fast.
Chances are you're considering purchasing an electric bike because they are generally perceived as faster than normal bikes. Well, these perceptions are mostly correct.
Nonetheless, being motorized forms of bicycles (having the capability to exceed normal bikes in terms of power), e-bikes are subject to regulations that limit their speeds. So, how fast are electric bikes, and are they really worth the hype?
What Is the Average Speed of an E-bike
The average speed for electric bikes is 20mph/32kph (both Class 1 and Class 2 e-bikes are limited to 20 mph). However, this number varies per manufacturer. Some e-bikes max out at 15mph while others can break past that threshold in seconds.
What Is the Top Speed of an Electric Bike
In theory, an electric bike's speed should only be limited by how much power the motor can generate. The case is different for pedal-assist electric bikes. The fact that they boost riders' efforts means they can go as fast as the rider can turn the pedals.
However, as vehicles designed to be ridden in public spaces, e-bikes are restricted to certain speeds to assure the safety of other road users.
In the US, federal laws categorize electric bikes into three different classes.
Electric bike manufacturers set these limits into their bicycle's smart control system. When an e-bike reaches its set top speed, the motor stops assisting. For example, you're riding a Class 2 e-bike up an incline. You engage the motor by twisting the throttle.
Immediately the bike's speedometer records 20mph (the speed limit for Class 2 e-bikes), current flow into the motor is restricted to maintain this limit. This doesn't mean the bike can't go faster. If you're powerful enough, you can pedal the bike to newer, higher speeds.
An electric bike's top speed shouldn't be confused with its "real speed limit" . Its "real speed limit" is the fastest its components (motor, wheels, pedals, etc.) can propel it to before they start to break.
How Fast Do Electric Bikes Go Without Pedaling
An electric bike can only travel as fast as 20mph without pedaling (however as we'll come to discover in subsequent paragraphs, this limit can be exceeded).
Using the throttle-assist function on an e-bike will propel the bike to 20mph before the controller limits the flow of current to the motor.
At this point, the rider can either choose to coast at that speed or pedal for more assistance to 28mph (Class 3 electric bike).
Local laws restrict throttle-activated e-bikes from going past 20mph. Some states in the U.S even prohibit these kinds of electric bikes from riding in public spaces.
What Determines the Speed of an E-bike
There are a lot of factors that determine the speed of an electric bike, listed below are some of them.
Voltage is the pressure with which charged electrons are released from a battery pack. It is the measured strength of electrons flowing through a circuit.
In the case of electric bikes, charged electrons from the battery cause the motors to spin. Pressure (Voltage) determines the flow of these electrons. So, more pressure/Voltage will mean more charged electrons flowing to the motor per second resulting in the motor spinning faster which translates into more speed.
This is why you'll find that, most times, electric bikes with higher volt battery packs are faster and more powerful than those with lower volts.
The size of an e-bike's wheel plays a huge role in how fast the e-bike can travel. Wide wheels improve traction but are more resistant to rolling than slimmer wheels.
Consider a 4-inch wide wheel with a motor integrated into it (a hub motor). The motor will have to do extra work to get this wheel spinning due to increased "wheel inertia".
This will impede the bike's acceleration and greatly affect the bike's performance when climbing up steep hills. Now, if we were to strap that same motor mentioned above to a slimmer tire giving out the same power as before, the bike will most likely perform better.
3) Motor Type
The two most common types of electric bike motors are hub and mid-drive. Hub-drive motors are integrated into a bike's wheel (front or rear) while mid-drive motors are integrated into the bike's frame, in-between the pedals.
Normally, you'd assume that e-bikes with hub motors are faster than those with mid-drive motors since their wheels are technically extensions of the motors in them. However, mid-drive systems connect to a bike's drivetrain giving them an advantage, in terms of speed, over hub-drive systems.
Mid-drive systems give riders the option to switch between different assisted gear ratios. So, let's assume you're on the biggest sprocket and the smallest cassette.
You have a gear ratio of 1:4 (for every revolution of the pedal, the wheel completes four full revolutions). This ratio will make the bike go faster but will require that the rider pedal harder.
Adding electric-powered assistance will reduce the amount of effort required to achieve a complete revolution of the pedals. This will in turn increase the wheel's RPM and propel the bike above speeds only bigger hub motors can achieve.
Do E-bikes Have Speed Limiters
Yes, e-bikes have speed limiters. Especially if the manufacturer wants the bike to be categorized as an "e-bike" and obey all biking rules.
There are some e-bikes, like Juiced's Hyperscrambler, that can be ridden as both e-bike and moped. These e-bikes can easily exceed the 28 mph limit for Class 3 electric bikes when their speed limiters are lifted.
Once a rider removes the limiters, they are no longer allowed to ride their electric bike in parks, trails, bike paths, or anywhere normal bikes are allowed. They can however ride their newly supercharged electric bikes on private property.
How Do You Remove the Speed Limiter on an Electric Bike
Some electric bike manufacturers include this as a speed mode that users can easily switch to from their LCD display. The Hyperscrambler calls this the "Race Track Mode".
However, not all e-bikes come with this functionality. De-restricting most electric bikes will require technical skills. These skills could range from identifying a sensor & magnet to playing with the bike's controller.
There are also e-bike de-restriction kits that riders can use to remove the speed limiter on their electric bikes. As mentioned above, most of these procedures require that the rider know a thing or two about electronics.