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Do you want to know if your electric bike belongs to the category of motor vehicle? This article will help you find a detailed answer to this question. Read below to learn all about it.
Yes, electric bikes are motor vehicles. The reason why we call e-bikes motor vehicles is the installation of an electric motor involved in their construction. This motor helps you save the energy you used for pedaling regular bikes. Without this motor, an e-bike would be the same as an ordinary bike, and you would have to spend more effort in pedaling it to your destination.
It is always good to know more about e-bikes especially when you are a die-hard fan of e-bikes and are interested in buying one. There are different parts to an e-bike, some of which are very essential, including the motor, battery, and other parts.
The e-bike motor is especially essential as it is the part that runs the e-bike without you needing to pedal. This article will shed light on different types of e-bike motors and the proper working process of e-bike motors. Read to the end to know the details of different types of e-bike motors and how they compare.
Is an electric bike a motor vehicle?
Yes, when talking about e-bikes as motor vehicles or non-motor vehicles, we always classify them in the category of motor vehicles because their construction involves a motor component that provides electricity to the e-bike. The type and size of the motor are not the same in all e-bikes. They change with the size and energy requirements of the e-bike.
How E-Bike Motors Work
Electric motors, in their simplest form, convert electrical power into mechanical power. E-bikes are propelled by brushless, direct current motors, or BLDC motors, which do not require brushes to switch the current direction passing to the motor, as previous electric motors did. Since brushes reduce the efficiency of the motors and tend to wear out across time, motor drives have been the industry norm for longer than a decade.
There are a lot of wires twisted about a round sequence of poles in a BLDC motor when you open it up. The stator creates an electromagnet when the battery current is drawn into wires by the motor controller. In addition to the stator, you’ll notice a circular array of permanent magnets. The rotor of a BLDC motor varies depending on the kind of motor, but regardless, the magnets always face the stator.
To understand how an e-bike motor works, you must understand the relationship between the stator and the rotor. The rotor spins because the stator’s electromagnets resist and attract the rotor’s permanent magnets when electricity flows through them in a circular pattern. A shaft connects the stator to the stator. A tiny chainring attached to the shaft of a mid-drive motor generates torque, which helps pedaling by spinning the shaft. Hub motors don’t have a spinning shaft since the axle is the shaft. An alternative is to use a motor (hub) that generates torque by spinning the rotor directly, rather than needing a generator.
The Different Types of Motors
Despite sharing a common core of technology, the motors used on today’s e-bikes exist in three basic configurations. Mid-drive motors are located in the center of the bike’s frame, where the bottom bracket is generally located. Hub-driven e-bikes feature motors integrated into the forward or rear hub, and they come in two flavors.
Apart from its bearings, direct-drive hub motors include no mechanical components: the motor simply rotates about the axle, which is fastened to the frame’s dropout. Geared hub motors reduce the motor’s revolutions per minute and boost its torque output by the employment of a sequence of planetary gears.
Additionally, there are alternative e-bike kits that enable you to connect a conventional bike with a semi or hub motor, and among the alternative kits are friction drives, which generate power via a spinning wheel that makes contact with the back tire.
Mid-drive motors are situated between the cranks of an electric bicycle. Electric motors provide torque, which is used to spin a shaft attached to a chainring. The engine is therefore augmenting your pedaling power inside the chain-drive system of the bike, rather than providing an extra source of power. Additionally, the motor pack contains a gear reduction mechanism.
Bosch mid-drive motors rotate hundreds of times a minute, considerably faster than the rider can pedal, but the motor’s internal gearing decreases the RPMs at the shaft, efficient to a rider-friendly cadence of 50 to 80 RPM, according to expert e-bikers. All but the cheapest mid-drive systems have gear sensors that limit power to the engine when changing gears to prevent the chain from breaking while the bike is not in gear.
2. Direct-Drive Hub Motors
The simplest type of e-bike motor is the direct-drive hub motor. The shaft of the engine serves as the back axle. Due to the stationary nature of the shaft, the motor revolves around it, driving you ahead. According to expert and professional e-bikers, direct-drive motors are often greater in size than geared hub motors since larger hubs result in increased leverage and torque outputs, which are required to provide appropriate power at lower RPMs.
Direct-drive electric bicycles may also create electricity when braking, a technique known as regenerative braking. “Motors are completely bidirectional,” professional e-bikers explain. “They are equally adept at moving forward and backward.” When the brakes are squeezed, a cutoff switch instructs the motor controller to transform into a generator, and the friction creates electricity. The energy gained from regenerative braking is negligible.
3. Geared Hub Motors
Unlike direct-drive hub motors, which spin at a considerably slower pace outside the hub, geared hub motors include an inside electric motor that rotates at a much faster rate. When the motor’s shaft is connected to a sequence of planetary gears, the hub is spun at a reduced speed. There is more torque but a lower top-end speed with this technique of power generation.
Due to the lower diameter of the geared hub motor compared to direct drive, the hubs are broader than direct drive hubs; however, this is due to the planetary gears. This implies that when the motors aren’t under power, they’ll coast easily rather than causing some drag, making geared hub motor-equipped e-bikes feel more like traditional bicycles when they’re not in use.
4. Friction Motors
If you’re looking for a cheap way to get an e-bike, a standard bike can be converted to an e-bike with no effort thanks to the low-cost friction-driven design. A tiny wheel attached to the tire is driven by a bolt-on motor, which is often located underneath the chain stays or before the seat stays.
It is the motor’s wheel that moves the tire ahead. Tire wear will rise as a result of the increased friction, although the interchangeability of the kits is a benefit. If you want an e-bike but don’t want to deal with a clunky and inefficient friction drive, an all-in-one kit like this from Alizeti is a great option.
5. DIY Systems
If you’re technologically inclined and don’t mind getting your hands dirty, you can retrofit almost any bike with a hub motor or mid-drive system. Choose the motor, method of pedal assist, and battery size to fit your needs with aftermarket e-bike kits.
The Bafang G310 geared hub motor is a favorite among e-bike manufacturers, for instance, and the entire DIY kit costs between $405 and $1,056, depending on your selection of components (and not including the battery). For less work, there’s the Copenhagen Wheel, a direct-drive hub motor, and rim that slides right into your rear dropouts.
Mid-Drive Motors Vs Hub Motors
You need to think about your priorities while choosing between a hub-driven and a mid-drive e-bike. These are just the advantages and disadvantages of each design.
- Mid-Drive Pros and Cons
In general, mid-drive e-bikes are better at climbing steep hills than hub-driven e-bikes since they may use the bike’s current geared drivetrain to benefit from increased low-speed gear reduction rather than augmenting it as an extra non-geared power source.
There are certain drawbacks to using a hub motor instead of a mid-drive when it isn’t rotating at its ideal RPM. For this, they can ride the bike with greater stability. That, coupled with their climbing prowess, makes them the engine of choice for e-mountain bikes. Since the frame and hub of mid-drive electric bikes are not wired together, riders may run any wheelset they like on their bikes.
Connecting a mid-drive motor toward a chain-driven bike has the potential to wear out the chain. The increased torque of an e-bike may need the replacement of your chain more frequently than with a conventional bicycle. Due to its greater gear drop and mechanical components, mid-drives are much more costly.
- Hub-Drive Pros and Cons
Unlike mid-drives, hub motors don’t wear down the chains and gears of a bicycle since they function outside of the chain drive. For one thing, mass-production means that they’re less expensive because the frame is not altered to accommodate a certain motor.
Direct-drive hub motors, in particular, are less efficient climbers than mid-drives. On the other hand, “if you’re going uphill at low speed, you’re wasting a lot of that energy because the engine is spinning as well,” experts explain.
Because direct-drive hub motors demand more watts, they require larger motors and battery packs, which increases their weight. Even so, the bike’s handling will be affected by the motor’s weight, and the weight distribution isn’t as centralized. This can be time-consuming since the cables that supply and operate the hub motor must be disconnected.
Direct-Drive Hub Motors Vs Geared Hub Motors
A geared or a direct-drive electric bicycle motor should be your first consideration when shopping for a hub-driven e-bike. There are advantages and disadvantages to every design.
When considering low-speed applications with high torque, gearless motors are superior whereas direct-drive motors are preferable for fast-speed applications with low torque. Since the internal RPM of a geared motor is greater than that of a direct-drive motor, a geared motor can be half the size of a direct-drive one with the same torque, according to professional e-bikers.
Because they are geared down for torque, direct-drive systems can withstand higher speeds and more power without becoming overstressed whereas geared systems struggle to reach the same peak speed. Experts say geared motors coast more easily than direct-drive motors, but the increased coasting resistance of a direct-drive motor is small; it’s like adding another pair of tires.
It is common for direct-drive motors to be tall and thin. High-speed applications benefit from a larger stator because it provides more leverage.
Due to the need for additional magnetic material to provide low-speed torque, direct-drive motors tend to be heavier and larger. However, this extra power and mechanical efficiency allow them to function at greater speeds. Although modern geared motors with the latest helical gears are practically inaudible as well, they tend to be quieter. As a result of regenerative braking, direct-drive vehicles can get some additional range and reduce brake wear.
What Do Power Ratings Mean?
Although there is no uniform norm for maximum or power rating duration, the power rating can suggest how often power you’re getting for a given length of time. Experts state, “That may be 10 seconds or 30 seconds.”. A 750-watt motor’s peak output may only last 1 to 2 seconds, according to the manufacturer.
In this article, we have talked in detail about the different types of motors of e-bikes available in the market. We have also mentioned their pros and cons to help you better decide which motor type is suitable for you and which is not. Hopefully, now you have got a better idea of e-bike motors. Best of luck with your next e-bike motor purchase. Also, for any further help, let us know your queries in the comments section below.