Views: 4 Author: Site Editor Publish Time: 2024-12-12 Origin: Site
At first glance, electric bikes are not much different than traditional bikes. They have a similar frame, two wheels, pedals, handlebars, and a traditional drivetrain. However, they also have a few components that you’re not likely to find on an ordinary bicycle.
The components in question are the electric parts such as the motor, battery, controller, throttle, pedal-assist sensors, and display. The motor is the heart of the electric system, whereas the other components center around it, allowing it to power the bike and assist the rider.
Let’s learn more about how these components work and what their roles are.
The motor is the most important electric component of any electric bicycle. It’s what gives you the power to overcome a steep hill, fight headwinds, or keep pedaling when you feel all your energy is drained.
Depending on how much money you want to spend and how you plan to use your electrically-powered bicycle, motors differ in terms of type and plac
ement.
The three main types of motors commonly found on modern electric bicycles are direct-drive, geared hub, and mid-drive motors.
Direct drive motors are the cheapest type you can get, but they come with some advantages and disadvantages. They’re usually placed either on the front or on the rear wheel, depending on the price of the bicycle. The cheapest e-bikes come with front-hub direct drive motors.
DD motors have no gears. This means that the motor makes one rotation every time the wheel makes one rotation. That’s a great solution on flat terrain while the wheel is spinning quickly because the motor can provide a lot of power. However, it’s a poor setup on steep hills when the wheel is spinning more slowly so the motor makes fewer rotations as well.
One of the benefits of DD motors is that they cool more efficiently, so they are often more durable than geared hub motors, even though they’re not as practical.
As you may guess, geared hub motors are placed inside the wheel hub and they have gearings. They’re commonly placed inside the rear wheel hub and are seen on mid-range electric bicycles.
The benefit of geared hub motors is that the motor can turn several times (typically around 5) for each rotation of the wheel, thanks to its geared nature. This is good for steep uphill rides because the motor can still deliver sufficient power, even though the wheel is turning slowly.
The disadvantage of this motor is that it does not dissipate heat as well as DD motors. The entire motor and gearing is placed inside a compact casing, which looks good, but traps heat even better.
Mid-drive motors are the best type you can get. As such, they’re often found on more expensive mid-range e-bikes and on high-end models.
Because mid-drive motors usually have torque sensors and supplement power directly to the pedals, they often feel more natural than hub motors. Torque sensors analyze how HARD you’re pedaling instead of how fast your wheels or pedals are turning, which means you’ll get assistance when you need it the most.
Mid-drive motors are also geared, though they have a separate gears housing, so they can be geared a lot lower than geared hub motors. That makes them the best choice for e-MTB and e-Road bikes.
These motors also have the ability to change the gearing ratio for optimal power output, which is what makes them the superior choice.
Another factor you need to consider when choosing which e-bike to get is the effect of the motor’s position on ride feel.
Namely, front-hub motors act similarly to front-wheel-drive cars. They’re nippy and responsive in the corners, but they don’t have as much traction as rear-wheel types.
Consequently, rear-hub motors improve traction because there is more weight on the rear wheel due to rider placement. They also provide more stable handling and need to be more sophisticated because they interact with the gears and other parts at the rear of the bike.
Finally, mid-drive motors are the best choice because they are located low, right under your center of balance. They make the bike more stable and make for a more natural riding feel.
The battery pack provides the motor with energy and determines the range. Batteries used to be big, expensive, and heavy, but they are usually none of those things today.
Modern batteries on expensive e-bikes usually fit inside the downtube, so they are placed completely out of sight. Cheaper models usually have batteries placed on the downtube or on the rear rack, plus they are heavier and don’t look as good.
Almost all modern electric bicycles come with lithium-ion batteries. However, in the past, e-bikes used to be powered by lead-acid, nickel-cadmium, or nickel metal hydride batteries. These are now considered to be outdated because they are heavier, less durable, and less eco-friendly.
Lithium-ion batteries are the same type that’s found in electric cars and most other electronic devices we use every day, including smartphones and laptop computers.
Battery capacity is usually measured in Amp-hours (Ah) or Watt-hours (Wh). The two basically measure the same thing, but Watt-hours is becoming the standard measurement because it is more consumer-friendly.
Since most e-bikes nowadays have 36V motors, you can easily convert Ah to Wh by multiplying the battery capacity in Amp-hours by the voltage of the motor. Thus, a 10 Ah battery usually equals a 360 Wh battery (10Ah x 36V = 360Wh).
Cheap electric bicycles can have a battery capacity in the range of 150–200Wh, whereas the most common range is 300–500Wh. More expensive models can have bigger batteries with capacities of over 600Wh, up to even 1,000Wh.
An exception to this rule is Rad Power bikes which are considered to be entry-level but have 672 Wh batteries, which is deemed quite high.
Depending on the manufacturer, battery capacity, and build quality, a full charge typically takes between two and a half and six hours. If your battery is at the higher end of this range, you can simply charge it overnight.
Lithium-ion batteries are usually rated for around 800 full charge cycles. That equals around three years of weekday commuting. However, most manufacturers claim that you can get around 2,000 half-charge cycles, which means that it is advisable to charge your battery whenever you get a chance.
With proper care, which means storing the battery away from extreme heat and cold, you can usually get even more life out of your pack.
Once the battery dies or its durability significantly decreases, you can simply replace it with a new one.
We won’t go into too much detail about controllers here. The reason is that they are a bit more complex than other components and not as important for beginners to understand.
A controller basically serves as a “bridge” between the battery and the motor, controlling the speed of the motor and the amount of power it drains from the battery.
Therefore, controllers are very important when it comes to the range of the bike, the amount of assistance a motor can provide, and the ride feel.
Pedal-assist sensors are another important part of electric bicycles that you should understand. Namely, there are two types of these sensors:
· Cadence
· Torque
A cadence sensor is basically a magnetic ring that attaches to the cranks and tells the motor how fast you’re turning the pedals. This way, the motor determines how much power to send your way. Cadence sensors are found on cheaper electric bikes because of their apparent downsides compared to torque sensors.
Torque sensors, on the other hand, tell the motor how hard you’re pedaling, which is why they are the superior choice. When the sensor detects you’re exerting more power on the pedals, it will instruct the motor to provide you with more assistance.
The last piece of the electric bicycle puzzle is the display. Most e-bikes use either simple LED displays or more complex LCD displays.
LED displays simply have a series of LED lights that show the remaining battery charge and the pedal-assist level, along with a few buttons to control the bike.
On the other hand, LCD displays are found on more expensive models and provide the rider with more options and more information. In addition to showing the pedal-assist level and battery charge, they can also track rides, showing distance, speed, time, odometer, and a few other functions.
The e-bike industry and the legislators in the US recognize three distinct categories of e-bikes. These differ in terms of having or not having a throttle, as well as in terms of the maximum assisted speed.
These three categories are called classes. However, it’s important to note that these “classes” have nothing to do with the product quality. Therefore, a Class 1 e-bike is in no way inherently better than a Class 2 or a Class 3 e-bike. They just have different characteristics and components.
Class 1 e-bikes are electric bicycles that are only pedal-assist and don’t have a throttle. These bikes have a maximum assisted speed of 20 mph. To go faster than that, the rider needs to turn the pedals and propel the bike solely with the power of their legs.
In parts of Europe, this Class is, in fact, limited to 15 mph with motor wattage up to 250W. In the USA, motor wattage is limited to 750W.
Class 1 e-bikes are usually city bikes that are meant for urban commutes and recreational riding. This is also the most common and the most affordable class of e-bikes. These bikes can generally be ridden everywhere a traditional bike is allowed, without any need for additional licensing.
Class 2 e-bikes have the same maximum allowed speed as Class 1 models, which is 20 mph. However, in addition to the pedal-assist function, they also have a throttle. Therefore, they can be ridden both as a pedelec and as an electric scooter.
Class 2 electric bicycles are less common than Class 1 models because they are usually more heavily regulated in many countries around the world. The throttle is usually added to cargo bikes and heavier city and mountain bikes to help riders pick up speed more easily when starting from a dead stop.
In parts of Europe, Class 2 e-bikes are considered to be motor vehicles, so they are banned from trails and other bicycle infrastructure. Their top speed is also limited to 15 mph, with motor wattage of up to 250W.
Class 3 e-bikes are pedal-assist only, but their maximum assisted speed is limited to 28 mph. They have no throttle, so the motor assists the rider only when the pedals are turning. This type is also called “Speed Pedelec”.
E-Road and E-MTB bikes are commonly built as Class 3 bikes because their riders are more performance-oriented and require higher maximum and average speeds. However, in some places in the US and around the world, Class 3 e-bikes are considered motor vehicles and require a license to ride.
