Some links may be affiliate links. We may get paid if you buy something or take an action after clicking one of these.
Electric Bike Modes: Throttle vs Pedal Assist (Pedelec)
Mar 22, 2023
Understanding E-Bike Propulsion Methods and Which is Right for You
Depending on their designation, e-bikes and their motors work in two ways: they can either make your level of pedaling effort easier, or completely take over and simply carry you along for the ride.
When you’re considering which type of e-bike to purchase, it’s important to think about which of these methods the bike offers, the environment(s) you’ll be riding in, and your own abilities and preferences. In this article, the writers here at Electric Bike Report will help you to understand the pros and cons of throttle vs pedal assist electric bikes, and help you to determine which is best for you!
Defining E-Bike Throttle and Pedal Assist Terms
Before we get into the differences between throttle and pedal assist and how they relate to you, let’s define those terms more clearly:
Throttle: a handlebar-mounted device that can engage (and sometimes adjust) power output from the bike’s motor. Electric bikes with throttles can be completely self-propelled, since throttles tell their motors to dispense power without the need for any pedal motion or input from the rider.
Pedal Assist: the standard method of operation for e-bikes. As the term suggests, this method of motor engagement requires the bike’s rider to move the pedals, though depending on the bike’s gearing, type of motor, and type of sensor, the rider may or may not need to actually be engaged with the drivetrain.
Pedelec: This term is a synonym for pedal assist, and is an abbreviation derived from the words “pedal electric cycle.”
It should be noted that, in order to be classified as electric bicycles, all e-bikes must have operable pedals. As such, most e-bikes function through pedal assist, with some having additional throttles – though it is still possible to have a throttle-controlled motor mounted to an otherwise non-electric bicycle with a standard drivetrain.
Many e-bikes, like the Aventon Aventure 2, offer both throttle and pedal assistance for a range of applications in different environments.
E-bike Class System
At least in the US, e-bikes are separated into three classes or categories. This class system plays a significant role in regulating their legal use in specific areas or on specific paths. Their placement within this system is determined by the methods through which they employ their motors, as well as their maximum motor-assisted speeds.
This system, and much of the legislation related to it, exists largely thanks to the incredible, thoughtful, and intelligent folks at People for Bikes. Their work has helped to create a structure for the governance, safety, and consistency of e-bikes, in addition to promoting them as beneficial to the well-being of all. If you can’t tell, we’re big fans!
Let’s take a look at how throttle vs pedal assist ties into this 3-class system.
A Class 1 e-bike has a motor that provides assistance only when its rider is pedaling, and is limited to motor-assisted speeds of 20 miles per hour. These e-bikes are capable of going faster than 20 mph, but only on human power beyond that point. These e-bikes do NOT have throttles.
Class 2 e-bikes ARE equipped with throttles, and do not require human input to be propelled (though most do also offer pedal assistance). E-bikes in this category are still limited to motor-assisted speeds of 20 miles per hour.
Sometimes known as S-Pedelecs or Speed Pedelecs (primarily in Europe), Class 3 e-bikes offer pedal assistance up to a maximum of 28 miles per hour. Additionally, Class 3 e-bikes are required to be equipped with a speedometer. Like Class 1 e-bikes, these can still be pedaled faster than their motor-assisted speeds, but only with human power.
Class 3 e-bikes can ALSO be categorized as Class 2 e-bikes if they feature a throttle that is limited to 20 miles per hour.
Thumb-operated throttle levers, such as this one on the Evelo Omega, are typically the most commonly-used variety.
Any e-bike that differs from the descriptions above falls into the “Unclassified” category. This could be for a number of reasons, such as including a throttle that reaches speeds above 20 miles per hour, or being equipped with a motor with nominal output beyond 750 Watts.
While laws and regulations still vary widely, e-bikes within this category are often only legal off-road or on private property without a license and registration.
Throttle Specifics, Pros, and Cons
As we established, an e-bike throttle is a control mounted on the handlebars that can control the motor. Throttles come in a variety of shapes and sizes, with differing degrees of functionality between them.
Most often, electric bike throttles come in two styles: either twist throttles or throttle levers. Twist throttles usually take up a portion of one of the handlebar grips, and are activated by rotating that portion (usually backward, for safety). Alternatively, throttle levers are a separate unit typically mounted next to one of the grips, and operated by thumb. We have occasionally seen button-style throttles as well, though these are less common.
E-bike throttles can apply their power in a couple of different ways. So-called “modular” throttles are adjustable, and apply more power and speed as they are twisted further, or their levers are depressed more. Others, usually the boost-button-style (but sometimes twist or lever-operated), function more like an on/off switch and apply power in an all-or-nothing fashion.
Additionally, throttles can sometimes be tied in with a bike’s electronic pedal assist system – we’ll cover more about that shortly – to set maximum throttle speeds below 20 miles per hour, if desired. This is a feature that we generally like to see, since keeping a twist throttle turned halfway or a throttle lever partially pushed down for a long period of time can be challenging.
Throttles are typically seen on bikes with rear-hub motors, though they do occasionally appear alongside mid-drives.
Some electric bike throttles come in the form of a twist throttle, like this one on the Lectric XPremium.
Pros of E-Bike Throttle Use
Since throttle engagement does not require pedaling, it places no strain on the knees and thighs. This makes electric bikes with throttles great for older folks or anyone with medical conditions that affect pedaling ability.
For cyclists who frequently find themselves in high-traffic environments, throttles can allow for swift startups that bring the bike up to speed quickly. This means keeping up with traffic more easily, and passing more safely through intersections.
If used on a Class 2 or 3 e-bike, throttle use allows riders to work less when encountering hills or headwinds, or to simply take a rest when needed.
Cons of E-Bike Throttle Use
Because the motor is the only thing powering the bike when the throttle is engaged, prolonged use can drain the battery much faster than when using pedal assist.
With throttles that are not tied into the bike’s pedal assist system, their speed may be difficult to keep consistent over extended periods of time.
When used with rear hub motors, throttles have fixed gearing that cannot be adjusted to suit the intensity of the rider’s environment.
Whether using an e-bike with a mid-drive motor or a hub motor, the bike’s pedal assist system (or PAS) will govern the amount of assistance the motor provides when pedaling. Generally speaking, this allows for an efficient system that divides the amount of work required to move the bike between the motor and the rider.
Pedal assist electric bikes typically offer multiple stages of assistance; most commonly between 3 and 5. The lowest settings are usually the most efficient and require less power from the battery, but this means that more human power is required to move the bike. Conversely, high PAS settings draw more power from the battery, but also require less pedal power as the motor dispenses a greater amount of assistance.
Depending on the size of the motor, the type of motor, and the PAS setting, using pedal assistance extends the limits of what a person can do on a bike. This can be as little as an additional 15-20% of what a rider is capable of, or it can skyrocket up to beyond 300%. This is what makes e-bikes so much fun!
Class 1 pedal assist electric bikes like the FLX Babymaker II do not include a throttle, and many are able to maintain a traditional non-electric bike feel.
Let’s quickly examine the types of motors, the different sensors they use to know how and when to provide pedal assistance, and how these things impact a bike’s feel.
As their name suggests, these are motors mounted in the center of either the front or rear wheel. Rear-hub motors are most common, and typically produce a feeling of being pushed from behind, though the intensity of this feeling differs depending on the motor’s size / power level. Due to their positioning, the amount of rider input that is needed with hub motors varies greatly, though this is related to the type of sensor they use – we’ll go over that soon. For those who want to learn more, check out our complete guide to hub motor brands.
Mid-drives are placed within a bike’s bottom bracket, and as such are tied directly in with its drivetrain through the cranks. These types of motors typically feature a much more natural ride feel much closer to that of a non-electric bike. They also tend to require a greater degree of rider input, which makes them typically more efficient than hub motors. Again, this depends on many factors, including their sensors. We go into more detail about this type of motor in our complete guide to e-bike mid-drive motors.
Cadence sensors, which are mostly found on hub motors, typically use a series of magnets or an optical system to detect pedal motion, and direct the motor to dispense power in tandem with the speed of crank rotation (rotations per minute, or RPMs). The PAS settings on a system with cadence sensors commonly set a “top speed” within each level that can be maintained with or without engagement with the drivetrain. As long as the pedals move, the motor supplies power.
Mid-drive motors with torque sensors, such as this one on the Quietkat Rubicon, commonly offer a much more natural and responsive pedal assist feel than a hub motor with a cadence sensor.
On the opposite end of the spectrum are torque sensors, which detect how much pressure the rider is applying to the bike’s pedals – essentially, how hard they are working – and tell the motor to supply power to compensate. In these cases, a bike’s PAS settings dictate how much power is dispensed with each pedal stroke. This results in a more natural and responsive pedal assist feel that pairs nicely with the sensation provided by a mid-drive motor, so it is no surprise that torque sensors are commonly used with motors of this type. That said, the technology is becoming more common on hub motors.
Pros of Pedal Assist
On e-bikes with motors that have well-tuned sensors, using pedal assist feels intuitive and nearly identical to riding a non-electric bike. This makes riding an e-bike an easy and fun skill to learn!
Using pedal assistance can provide a great workout and all of the health benefits that come with it!
When compared to throttle use, pedal assist is typically more efficient, meaning that it requires less battery power and can allow a bike to travel farther.
Considering that most e-bikes have more than a single speed, pedal assist can take advantage of both a bike’s gearing and PAS to adapt its feel to its environment.
Cons of E-Bike Throttle Use
Using only pedal assist when starting can be much slower than throttle use, making city rides a bit more difficult.
Depending on the motor and the type of sensor it uses, the bike’s motor responsiveness can vary greatly.
Managing a bike’s gearing and PAS setting can take some effort and practice to master.
Where to Go Next
We hope that you have found this article helpful! When you’re considering the differences between a pedal assist electric bike and an electric bike with a throttle, you’re really only scratching the surface of what makes them unique.