Of course, you already know that every electric bike comes with a motor. But what types of motors are there? What difference does the motor placement make? How do you know which one is right for you?

We have compiled a general introduction to e-bike motors and classifications (without technical jargon) to assist you in making a decision. Keep reading!

Motor Classifications

Despite using the same basic technology, there are three main types of motors found in today's electric bikes. The mid-drive motor is located at the center of the bike frame, typically at the bottom bracket. Hub-drive e-bike motors are located within either the front or rear hub, and hub motors come in two types.

Direct-drive hub motors have no moving parts other than the bearings: the motor simply rotates around an axle fixed to the bike’s fork or frame. Geared hub motors use a series of planetary gears to reduce motor speed and increase torque output. All EAHORA Ebike motors are geared motors.

You will also find aftermarket e-bike kits that allow you to equip a standard bike with either a mid-drive or hub motor, and among aftermarket kits, there are friction drives, which use a rotating wheel in contact with the rear tire to generate propulsion.

Mid-Drive vs. Hub Motors

Mid-Drive Motors

Mid-drive motors are located between the cranks of an electric bike. The torque generated by the motor causes the axle connected to the chainring to rotate. Therefore, the motor supplements your pedaling power within the bike's chain drive system, rather than adding an extra power source. The motor unit also includes a reduction system. Bosch's mid-drive e-bike motors rotate hundreds of times per minute—much faster than you pedal—so the internal gearing reduces the axle speed, optimizing the system's performance to a rider-friendly cadence of 50 to 80 RPM. All but the most basic mid-drive systems include a gear sensor that cuts off power when you shift, preventing chain breakage when the bike isn't in gear.

Direct-Drive Hub Motors

Direct-drive hub motors are the simplest type of e-bike motors. The motor shaft acts as the rear axle. As the shaft is fixed in place, the motor (or hub) rotates around it, propelling you forward. Direct-drive motors tend to have a larger diameter than geared hub motors because a larger hub means more leverage and greater torque output, necessary for delivering sufficient power at lower speeds. Direct-drive e-bikes can also generate electricity during braking, a process known as regenerative braking.

Geared Hub Motors

Geared hub motors operate similarly to direct-drive hub motors, with the difference being that the motor inside the hub rotates at a much higher speed. The motor's shaft connects to a series of planetary gears that are linked to the hub, causing it to rotate at a lower speed. This approach generates more torque but results in a lower top speed.

Geared hub motors typically have a smaller diameter than direct-drive motors because they don't require as large a motor to produce the same torque on the wheels, although the planetary gears make the hub wider. These motors also include a freewheel: this means there's no possibility for regenerative braking, but they can coast freely when not powered, instead of creating slight resistance, making e-bikes with geared hub motors feel more like traditional bicycles.

Advantages and Disadvantages of Mid-Drive Motors

Generally, mid-drive motors are more effective than hub-drive motors for climbing steep hills because they utilize the bike's existing gear system to take advantage of higher gear reductions for low-speed climbing, rather than supplementing power as a non-geared source. (The efficiency disadvantage arises when hub motors do not spin at optimal speeds—a powerful geared hub motor should be as efficient as a mid-drive.) The central positioning on the bike also creates a more balanced riding experience.

It's easier to change tires on a mid-drive e-bike since there are no wires between the frame and the hub, allowing users to run any wheelset.

The downside of adding a mid-drive motor to a chain-driven bike is increased chain wear. Reputable e-bike manufacturers do not cut corners on chain quality, but the added torque means you might need to replace the chain more frequently. Mid-drive systems are also more expensive because they contain more mechanical components and higher gear reductions, which increase costs.

Advantages and Disadvantages of Hub-Drive Motors

Since hub motors operate outside of the bike's chain drive system, they do not wear out the chain and gears like mid-drive systems. Hub motors are also cheaper because they can be mass-produced and do not require manufacturers to change the frame to accommodate specific motors.

Hub motors, particularly direct-drive ones, are less efficient for climbing compared to mid-drives. If you climb hills at low speeds, the motor also spins slowly, meaning much of the power converts to heat rather than forward motion. Direct-drive hub motors require more power, necessitating larger motors and batteries, which add weight.

Weight distribution is also less centralized, though the impact on bike handling depends on the motor's weight. Finally, changing tires can be cumbersome because you need to disconnect the wires powering and controlling the hub motor.

Different Types of Assistance

When browsing electric bikes, you may notice that the two most popular types are throttle-assist models and electric-assist models.

Throttle-assist models typically feature a handlebar twist throttle like a motorcycle or a thumb-operated throttle lever. When the engine is engaged, it provides power on demand to propel the bike, requiring no pedaling from the rider.

Meanwhile, electric-assist models, also known as pedal-assist, pedal-electric bikes, or simply pedelecs, are the ones that truly require pedaling. In these bikes, the motor provides power only when you pedal, and you can control the amount of power (assist) received from the motor based on how hard you pedal. EAHORA electric bikes are all throttle-assisted.

In summary, both types of e-bikes allow you to conquer hills you might have avoided on a traditional bike and reach farther destinations without exhausting yourself. They are more environmentally friendly and can save you money in the long run compared to owning a car, among other benefits (see our "5 Reasons to Ditch the Car for an E-Bike"). However, you might consider an electric-assist model over a throttle model if:

1.You are accustomed to riding a traditional bike and prefer a more intuitive riding experience.

2.You need an e-bike that truly encourages pedaling for better physical health.

3.You want an e-bike that can travel more miles (assuming both bikes have the same motor and battery size, pedal-assist models can go farther than throttle models with pedaling power).

4.Your local e-bike regulations prohibit the use of a throttle on e-bikes.

How Are E-Bikes Classified?

While e-bikes are still in their infancy, the laws governing them are even more embryonic. Most U.S. states lag behind public understanding of e-bikes compared to mopeds or electric motorcycles. Efforts to legalize these differences began with some simple questions that were initially unanswered: Are electric bikes allowed on bike paths? What about in parks? How fast can I ride? Few states had clear answers, and opinions varied widely.

Since then, the e-bike industry and more than half of U.S. states have come together to create a common but broad classification system—Class 1, Class 2, and Class 3—advocated by the industry association PeopleForBikes. Nevertheless, if you're concerned, check your local laws to ensure compliance with e-bike regulations. You're unlikely to be stopped for riding at 22 mph on a bike path or using an e-bike in the wrong lane, especially if it resembles a regular bicycle, but it's better to be safe.

CLASS 1

Class 1 electric bikes have a top speed limit of 20 mph, and the motor only works when the rider is pedaling. These bikes are known as pedal-assist bikes since the motor provides assistance only when pedaling. Some bikes have a throttle on the handlebar for extra power, but for Class 1 e-bikes, the throttle only works when pedaling. You don’t need to pedal strenuously; you can set it to a low gear and gently spin the pedals forward to engage the throttle.

Class 1 e-bikes can be ridden on bike paths and lanes shared with traditional non-assisted bikes, which we now refer to as analog bikes.

CLASS 2

Class 2 electric bikes also have a top speed limit of 20 mph, but their throttle can work even when you are not pedaling. This doesn’t mean that the motor won’t assist you if you decide to pedal. Most Class 2 e-bikes offer pedal-assist in addition to the throttle. Like Class 1 e-bikes, you can usually ride them in the same locations as analog bikes.

CLASS 3

This is where it gets confusing. Class 3 electric bikes can reach speeds up to 28 mph and must have a speedometer, but they might or might not have a throttle. This depends on state regulations. For instance, California does not allow Class 3 e-bikes to have a throttle at all. In other states, a throttle is permitted as long as the maximum speed with the throttle does not exceed 20 mph, while pedal-assist power can continue up to 28 mph. Most states allow you to ride Class 3 e-bikes on bike lanes or paths on the roadway or shoulder (so-called curb-to-curb). However, you cannot ride them on bike paths or multi-use trails shared with pedestrians, like in parks.

Some e-bikes try to navigate these limitations by adding a mode that limits speed to 20 mph, allowing you to ride on multi-use paths and trails. Switching settings or removing a specific physical key can unlock the bike’s full potential.

All EAHORA EBIKE models are Class 3 e-bikes, so purchase according to your needs.

How to Unlock Higher Top Speeds?

E-bike manufacturers often engage in an unregulated trend of doing as they please. Did you know some e-bikes can reach speeds of 60 mph? At that point, they are essentially electric motorcycles with extra pedals. More and more high-speed e-bikes can exceed the 28 mph speed limit but still find a technical, legal way to fit within the classification system through switchable settings and some rider cooperation.

This is where the honor system comes into play. Many e-bikes, like the Eahora ROMEO and JULIET series, allow you to remove the speed limit, provided you promise not to ride on bike lanes. Alternatively, they inform you that unlocking is permissible only on private property. Unlocking is easy, typically done via the bike's display or a companion app. Most e-bikes exceed their class limits by just a few mph, but other e-bikes, like the HPC Black Lightning, can far exceed 28 mph. This is why some manufacturers can sell e-bikes with speeds up to 40 mph and motors many times more powerful than standard e-bikes while still meeting regulations. You switch a setting, and it suddenly becomes a Class 2 or Class 3 e-bike, at least legally.

If your e-bike settings don't comply with local regulations, do not use an unlocked e-bike on bike paths or around pedestrian-populated parks. You don't want to collide with anyone, and for your own safety, you shouldn't ride too fast to avoid being unable to react in time to sudden obstacles like people, pigeons, or Porsches in your path.

Choose Your E-Bike Wisely

Now you know the basics about choosing an e-bike regarding motors and bike classifications. Eahora e-bikes are all Class 3 and equipped with geared hub motors. Powered by engines, e-bikes offer a practical, sustainable, and enjoyable mode of transportation for people of all fitness levels. Just look at the smiles on the faces of those riding e-bikes! However, before investing your hard-earned money in an e-bike, it is crucial to understand the facts so you can make a confident decision. Click here to choose your e-bike!

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