Guide
Electric Bike Motor Guide
Jul
The Motor: A Vital Component
The motor, undoubtedly one of the most essential elements on any ebike, has witnessed numerous changes throughout the years. In order to efficiently propel an electric bicycle, the motor must be designed properly. Just like with cars, ebike motors can be mounted at the front, middle, or rear of the bike, and they come in all shapes and sizes. The two most popular types of motors found on ebikes are hub and mid-drive motors. Hub motors, in particular, have two main variations: geared hub motors or direct drive motors. While these are the most popular types, there have also been other variations, such as friction-based rear-mounted motors, that have seen some use over the years.
Benefits and Shortcomings of Each Variation
Each type of motor variation comes with its own advantages and potential drawbacks. For instance, someone who commutes on relatively flat pavement will find that a direct drive motor is the most efficient option. However, someone in need of a full suspension electric bike for downhill mountain biking would not be interested in a direct drive motor.
In order to gain a better understanding of each motor variation, let us delve into the history of electric bike motors and explore more information about each style.
The Rich History of Ebike Motors
Bicycles have been in existence for centuries. It was only a matter of time before humans invented a system that allowed for electric assistance when propelling a bike forward. In the late 19th century, in France, one of the earliest electric bicycle patents introduced a hand-lever system to propel the bike without pedals. This patent served as inspiration for inventors worldwide, leading to the creation of some of the first electric bikes.
The first known rear-mounted hub motor was patented in 1895 by Ogden Bolton Jr. This motor was mounted in the rear wheel, which remains a common system in today’s technology. Ogden’s patented design utilized a magnetic system and is considered one of the earliest direct drive motor designs.
In 1897, Hosea W. Libbey patented the first documented mid-mounted motor, similar in some aspects to modern mid-drive motors. The battery for this design was mounted in the middle of the bike, between the top and bottom tube of the frame, and powered the mid-mounted motor.
Shortly after, in 1899, John Schnepf patented the first friction drive motor. This design aimed to create a friction-based system for greater electric propulsion. It involved a roller mounted on the rear tire that derived energy from the friction produced by the moving wheel. This concept is similar to the friction drive motors found on some ebikes today.
The Geared Hub Motor
Below is a chart outlining the pros, cons, and ideal situations for a geared hub motor.
| Pros | Cons | Best For |
| Geared hub motors are generally a durable option |
Slightly less efficient than Direct Drive motors |
Most effective on ebikes in the 250W to 1000W range |
| A geared hub motor offers a high amount of low-end torque | Can make removing the rear wheel more difficult than some other motor styles | Great option for bikes designed for off road purposes or those that need to tackle any type of elevation gain |
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Motor power does not travel through the bike chain so there is no additional stress or wear the drive train |
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Internal clutch allows the motor to freewheel when traveling at high speeds |
Rad Power Bikes and Their Geared Hub Motor
Rad Power Bikes has chosen to utilize a geared hub motor for their RadRover, RadMini, RadMini Step-Thru, RadRunner, and RadRunner Plus models. This type of motor is a favorite among ebike companies because of its durability and affordability, as well as its excellent low-end torque capabilities. In fact, many ebike companies opt for either a geared hub motor, a direct drive motor, or a mid-drive motor. Each of these motor types has its own advantages and disadvantages that cater to different rider situations.
Advantages of a Geared Hub Motor
A geared hub motor is particularly well-suited for off-road or rough terrains, as well as uphill and downhill rides. It offers a substantial amount of low-end torque, similar to a mid-drive motor. This increase in torque allows the bike to smoothly conquer uphill climbs and maneuver through uneven terrains effortlessly. In fact, a geared hub motor is technically the fastest motor available in the market. Additionally, its internal clutch system disengages the magnets when going downhill, enabling the bike to have the fastest downhill free-wheel capability.
Limitations and Cost-effectiveness
While a geared hub motor may not deliver the highest performance rate compared to a mid-drive motor, it still provides a commendable level of performance. It is an affordable option that offers great value for money. However, those seeking the utmost performance and dual suspension should consider a mid-drive motor. Nevertheless, if you’re looking for a budget-friendly option that delivers excellent performance, a geared hub motor is a wise choice.
The Benefits and Limitations of a Direct Drive Motor
Now, let’s explore the advantages, drawbacks, and the ideal scenarios for a direct drive motor.
Advantages
– This motor type has fewer components, making it the most durable option available.
– It allows for regenerative braking, providing an additional energy-saving feature for the rider.
– It is the most efficient motor for longer, high-speed trips.
Disadvantages
– A direct drive motor may not offer as much low-end torque as a geared hub or mid-drive motor.
– Removing the rear wheel can be more challenging compared to other motor styles.
– The freewheeling capabilities of the bike are reduced.
Best Scenarios for a Direct Drive Motor
A direct drive motor is an excellent option for city commuters who cover longer distances without many hills or inclines. It is also suitable for riders who desire regenerative braking functionality. However, it’s important to note that the freewheeling capabilities are intentionally reduced to prevent achieving high speeds that could potentially cause a breakdown situation within the controller. Therefore, the controller needs to be more durable to handle this reduced freewheeling capability. Luckily, most kits and electric bike manufacturers have already installed the necessary engineering to handle regenerative braking, alleviating any concerns for the user.
In conclusion, Rad Power Bikes has carefully chosen to offer a range of motor options to cater to different rider needs. Whether you opt for the durability and affordability of a geared hub motor or the functionality and efficiency of a direct drive motor, you can trust that Rad Power Bikes has considered your riding experience and satisfaction.
A Direct Drive Motor
A direct drive motor is at its peak efficiency when running at top speed. However, it is less efficient compared to other types of motors when it comes to reaching that speed. This means that for longer commutes with minimal stops or inclines, a direct drive motor is the most efficient choice.
| Pros | Cons | Best For |
| Geared hub motors are generally a durable option |
Slightly less efficient than Direct Drive motors |
Most effective on ebikes in the 250W to 1000W range |
| A geared hub motor offers a high amount of low-end torque | Can make removing the rear wheel more difficult than some other motor styles | Great option for bikes designed for off road purposes or those that need to tackle any type of elevation gain |
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Motor power does not travel through the bike chain so there is no additional stress or wear the drive train |
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Internal clutch allows the motor to freewheel when traveling at high speeds |
Mid Drive Motor
Below is a chart that outlines the advantages, disadvantages, and the best situations for using a mid-drive motor.
| Pros | Cons | Best For |
| Has few components making this the most durable option | Does not offer as much low-end torque when compared to a geared hub or mid drive motor | Great option for city commuters who have longer distances to cover without many hills or inclines |
| Can make removing the rear wheel more difficult than some other motor styles | Someone who wants to utilize regenerative braking | |
| This type of motor allows for regenerative braking. | The bike’s freewheel capability is reduced | |
| The most efficient motor in longer, higher-speed trips | ||
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Is the most quiet type of motor
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You might wonder which option to choose between a geared hub motor and a mid-drive motor, considering they offer similar torque levels. The answer depends on various factors, mainly price and performance. A mid-drive motor is more expensive but delivers top-notch performance. It is best suited for high-performance ebikes where the rider’s input plays a crucial role due to the motor’s placement, which utilizes the chain and pedals.
It is worth noting that a mid-drive motor has some downsides aside from its high cost. One significant drawback is its impact on the chain. Unlike other motor types, a mid-drive motor transfers power through the chain, subjecting it to more stress. This can lead to chain breakage, rendering the bike unrideable. In contrast, if a geared hub or direct drive motor breaks the chain, which is less likely, you can still use the throttle function to ride the bike. Furthermore, the majority of mid-drive ebikes lack a throttle function altogether.
Front vs Mid vs Rear Mounted Motor
Electric bike motors can be mounted at the front, middle, or rear of the bike. Each mounting position has its own advantages and disadvantages. The following charts outline the reasons to consider and avoid each mounting placement.
| Pros | Cons | Best For |
| Offers a good amount of low-end torque | Is the most expensive option and the most expensive motor for maintenance costs | High-performance bikes |
| Can offer the highest peak performance of any other motor | The motors power runs through the chain, which puts more stress on the chain than any other motor type | Full suspension ebikes |
| The rear wheel does not have the added weight of a motor and is generally easier to remove | If the chain breaks on a mid-drive motor, the bike is no longer rideable. Hub motors with throttles can still be propelled by the throttle if the chain breaks | Ebikes with a 250W motor or ebikes in need of 1000W and above |
| When freewheeling, the bike will actually feel like a normal bike since the chain won’t be moving in a coasting situation | Great option for bikes designed for off-road purposes or those that need to tackle any type of elevation gain |
Front Mounted Hub Motor
Pros
– Provides enhanced traction and stability.
– Simplifies rear-wheel removal since it doesn’t add extra weight.
Cons
Places less stress on the rear axle which may allow for a solidified mounting point for a bike trailer or tow behind
The placement of the ebike motor towards the rear of the bike reduces the strain on the rear axle, resulting in a more secure attachment point for a bike trailer or tow behind. This ensures stability and strength during transportation.
Front mounted motor – considerations and effects
Front forks are not typically designed to handle the additional stress of an ebike motor. Therefore, it is important to be aware of potential limitations when using this configuration. The motor’s weight on the front of the bike can make it feel heavier and impact the steering, affecting the overall balance and maneuverability.
| Pros | Cons |
| Places less stress on the rear axle which may allow for a solidified mounting point for a bike trailer or tow behind | Front forks are not typically designed to accommodate the extra stress of a ebike motor |
| If the chain breaks, you can still use the motor through either the cadence sensor or throttle | A front mounted motor applies more weight in the front of the bike and makes the bike feel heavier as well as affecting steering |
| Cannot go over bumps or pop curbs with the added weight of a front mounted motor | |
| Makes removing the front wheel more difficult with the added weight and the absence of a quick release; instead utilizes a bolting system | |
| Torque arms cannot easily and aesthetically be added to front fork dropouts |
Mid Drive Motor
When considering different ebike motor options, the mid drive motor stands out as a viable choice.
| Pros | Cons |
| Best weight distribution | Places more stress on the bike chain |
| Does not place added stress to the front or rear hub of the bike | If the chain breaks, you will be stranded |
| Allows for easy access to both the front and rear wheel | Increase wear rate of other drive train components such as the front sprocket and rear cassette |
| Allows for coasting without any motor resistance |
Rear Mounted Hub Motor
Another popular option for ebike motors is the rear-mounted hub motor.
| Pros | Cons |
| A rear-mounted hub motor can better handle the extra weight and components of the motor when compared to a front mounted motor | Use of trailers mounted to the axle potentially compromised due to the presence of motor cable and additional motor mounting hardware |
| Does not put added stress on the front fork | |
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If the chain breaks, you can still use the motor through either the cadence sensor or throttle |
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Keeps weight low and towards the back of the bike for smooth bike handling
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Conclusion
In conclusion, it is crucial to consider the type of ebike motor that best suits your riding needs. Each motor configuration has its own advantages and potential drawbacks. At Rad Power Bikes, we offer Geared Hub Motors and Direct Drive motors to cater to a wide range of riders, ensuring optimal performance and enjoyment of your ebike experience.
