When you’re on the hunt for an e-bike, chances are that you’re going to be greeted by a plethora of unfamiliar terms. You may see things like ‘hub motor’, ‘torque’, or ‘pedal assist’. These are terms that, quite frankly, can be rather baffling to newcomers. They’re terms that you need to understand when you buy an e-bike, though. They’ll give you a solid idea of what you are buying, how it will function, and even the situations the bike can be ideal for.
On this page, we want to introduce you to the most important e-bike terminology. We’re going to explain things as simply as we can. So, don’t worry if you’re new to e-bike tech. It shouldn’t take that much effort to ‘follow along’.
Key Components of an E-Bike
We’re going to start by looking at the main components of your e-bike. When you’re looking to buy an e-bike, you’ll see all of this information included in the specs. By knowing what you’re looking for, you’ll get a rather solid idea of how good the e-bike actually is.
At the heart of any e-bike will be the motor. There are three things that you’ll need to be on the lookout for here:
- The position of the motor (whether it is a hub motor or a mid-drive motor)
- The power output of the motor (measured in watts)
- The torque of the motor (measured in Nm)
Let’s explain what this all means.
Hub motors are mounted at the rear of the bike. They tend to be much smaller than mid-drive motors, which means they do put out less power. However, they are much lighter weight. E-bikes kitted out with a hub motor tend to feel (and look) much more like a traditional bike. So, they are for people that want a light amount of pedal assistance, and who will be doing the bulk of the pedaling themselves.
Mid-drive motors sit in the middle of the e-bike (near the bottom of the bike’s frame). They are heavier than hub motors, although more modern iterations of mid-drive motors can still be quite lightweight.
Mid-drive motors provide more power than hub motors. Because they are often placed in a position that is at the center of gravity, it also becomes a lot easier to control a bike with a mid-drive motor. There’ll be less swaying back and forth.
Power Output (Watts)
The wattage on an e-bike is the amount of power that the motor delivers. The more power, the more it can assist the rider. It will even help the e-bike travel faster. However, do bear in mind that there are strict laws in place when it comes to wattage. In most countries, street-bound bikes can have a maximum of 250W to 500W in output. This is more than enough to ride with, in most cases. If you’re going off-road, you may need a bit more power (some off-road e-bikes have a maximum of 1000W of power).
Torque is the amount of force the motor uses to rotate the wheel. The higher the torque on an e-bike, the higher the acceleration. If you’re going to be spending a lot of time off-roading, or traversing steep hills, you’ll often need an e-bike with a higher amount of torque on it.
There are four things you want to be on the lookout for in a battery.
Battery Capacity (Ah)
The battery capacity will be listed as Ah. The higher this number, the better. However, a higher battery capacity will also translate to a more expensive battery. It’ll also be a lot heavier.
High-capacity batteries have a longer range (we’ll discuss that soon). This means that you’ll be able to ride further before you need to charge it. However, the higher capacity does mean that the battery will take longer to charge.
Battery Voltage (V)
The battery voltage indicates the amount of power flowing from the battery to the motor. The higher the voltage, the more efficient the power delivery is. This gives the motor more to work with. A higher battery voltage often translates to more speed and better performance on hills and off-road.
While ‘more power’ may seem like a good thing, it isn’t always the case. Higher battery voltages often have lower capacities, which means a lower range. Ideally, you would want a bike at either 24V or 36V for long-range cycling, and 48V or 52V for off-road cycling where range doesn’t matter.
Battery Range (Miles)
All e-bikes will list a range. This is the amount of distance you could expect to ride the e-bike under ideal conditions on a single charge of the battery. However, do bear in mind that you are unlikely to ever be riding in ideal conditions. Most of the time, the range of the e-bike will be far lower than quoted.
However, the ‘range’ will allow you to make quick comparisons between various e-bikes. The higher the range, the better the e-bike is for long-distance cycling.
Battery Type (Battery Chemistry)
We won’t dive too deep into battery chemistry here. All you really need to know is that each type of battery chemistry delivers power using a different combination of materials. The battery chemistry will impact the operation of the battery, the lightness, and the cost. There are three main battery chemistries you want to be on the lookout for when it comes to e-bikes (there are a few more, but they are rarer).
The cheaper e-bikes will have NiCd batteries. NiCd batteries are incredibly cheap to produce, although they have a few downsides. For starters – they are heavier. This makes the e-bike heavier and could have an impact on the range of the bike. Over time, they’ll also suffer from a significant power loss and charge capacity, so you’ll need to replace NiCd batteries a lot more frequently.
NiMh batteries are one step up from NiCd batteries. They are much lighter than NiCd batteries, and they’ll often continue to deliver roughly the same amount of power for the duration of the battery’s life. While they may suffer a loss in charge capacity over long-term use, it isn’t really a major issue.
The downside is that these batteries are more expensive than NiCd (you’ll often find them on mid-range e-bikes), and they don’t hold their charge all that well if left in storage. On top of this, they often won’t last as long as the other two battery types.
The best e-bikes will feature Lithium-Ion batteries (or some variation of Li-Ion technology). These batteries are lightweight and can deliver a huge amount of power. Battery manufacturers can often pack a huge amount of battery capacity into a tiny battery.
Lithium-ion batteries tend to hold their charge well, and you shouldn’t really see a fall in battery voltage (or at least a noticeable fall) for the duration of battery ownership. Not to mention the fact that Lithium-Ion batteries don’t see a fall in charge capacity.
On top of all of this, Lithium-Ion batteries tend to last longer. They often have 1,000-2,000 charge cycles in them (the other two battery types may have half of this).
The controller is the ‘brain’ of your e-bike. The controller is a collection of circuit boards and sensors.
The controller does a lot of different things. However, it pretty much boils down to keeping tabs on what the user is doing (or what the user has requested through the movement of the throttle, interactions with the e-bike’s computer, etc.)
Using a collection of sensors (including speed, braking, user inputs, pedaling, etc.) the controller will tell the battery how much power to deliver to the motor. This ensures that only the right amount of power is sent to the motor.
The controller is a pretty complicated piece of kit, and the controller can often mean the difference between a good and a great e-bike.
Pedal Assist System (PAS) or Throttle
Your e-bike will have either a pedal-assist system or a throttle control (sometimes, it will have a combination of both)
A pedal assist system will be mostly pedal-driven. This means that you still need to do a bit of pedaling. The e-bike will then ‘top up’ the pedal power. This means that you can travel faster, even if you are only doing a bit of light pedaling. It means that you need to expend less effort to travel at greater speeds. Pedal assist e-bikes often have the greatest range because the battery doesn’t drain as quickly (as it won’t be needed as much).
Throttle-assist e-bikes will have a throttle on the handlebar. There is no need to pedal. Just twist the handlebar and away you go. These bikes will often have a lower range than pedal-assist bikes as the e-bike will need to use a lot of power to keep the motor running. On the plus side, you don’t really have to put any effort into cycling a throttle-assist e-bike. Just sit on it, steer, and the bike will do the rest of the work for you.
Almost every e-bike will have a display or a console on it. This will give you various information, including:
- The speed you are traveling at.
- How much power is left in the battery?
- Whether you have pedal assist turned on.
- Cadence (i.e., how often you are spinning the pedals).
The exact information will vary from e-bike to e-bike. It all depends on the sensors included in the e-bike. So, make sure that you do your research into the display/console on your selected e-bike.
Assist Levels and Modes
Your e-bike will have various assist levels and modes. Let’s tell you what each of them means. Do keep in mind that not every e-bike will include everything that we have listed here.
Pedal Assist Level
The pedal assist level will be how much ‘assist’ you want from the motor when pedaling. The lower the pedal assist level, the more effort you’ll need to put into pedaling. However, your bike’s range will be higher. High pedal assist levels will mean that you barely need to cycle to hit the top speed, but your battery won’t last as long.
Eco mode is often the name given to a low pedal assist setting. As before – low pedal assist means that your e-bike’s battery will last longer, but you’ll put more effort into cycling. Your e-bike’s controller will often keep tabs on how fast you are pedaling and lower (or raise) the e-bike’s motor power to suit.
Normal mode will be around the halfway point of the pedal assist settings. The e-bike will try to maintain a balance between pedaling and motor assistance. This is where most average cyclists will keep their pedal assist. It means that they still need to put in effort to ride, but not too much.
How boost mode works will be dependent on the e-bike. Most e-bikes see the boost mode as offering a very quick bit of speed to the bike. This allows you to get up to cruising speed quickly or have a slightly higher amount of speed (for a few seconds) to tackle hills a bit easier or deal with some of the trickier obstacles on off-roading courses.
Boost mode will drain the battery very quickly, so you’d want to use it sparingly.
E-bikes can be broken down into three different types (sometimes called classes). When you look at the type rating of an e-bike, you’ll get an idea of how that e-bike is expected to be controlled.
We’re going to look at the three different types of e-bikes here. We’ll also let you know if there is any specific legislation that may impact who can ride that e-bike. However, do bear in mind that the rules can vary from country to country. We are looking at things from a purely American perspective here, so if you are outside the US, then you may find the rules are slightly different from yours. This means that you will need to research things further.
Type 1 E-Bikes
Type 1 E-Bikes are:
- Pedal-assist or throttle-controller.
- Have a maximum speed of 20mph.
These are the slowest e-bikes, and to operate them you will likely need to pedal. While there are some throttle-controlled type 1 e-bikes, these are very rare.
Because Type 1 e-bikes mostly require pedal assist to operate, they often have the best battery life. In some cases, you may even find Type 1 e-bikes to be among the cheapest of the available e-bikes.
There are no special restrictions governing who can ride a Type 1 e-bike.
Type 2 E-Bikes
Type 2 E-Bikes are:
- Only throttle-controlled (no pedal assist).
- Maximum speed of 20mph.
These e-bikes only have a throttle. While they may have some pedals for aesthetics, pedaling isn’t really going to be doing anything for you (other than giving you some exercise, we guess). These e-bikes operate more as a motor vehicle than a bike, and they are often favored by those people doing their daily commutes.
There are no special restrictions governing who can ride a Type 2 e-bike.
Type 3 E-Bikes
Type 3 E-Bikes have:
- Pedal assist (but may also have a throttle).
- A maximum speed of 28mph.
These e-bikes are essentially Type 1 e-bikes with a little bit of extra speed. In the US, you must be at least 17 to ride one of these, and you are legally required to wear a helmet.
Charging and Maintenance Terminology
There are a few things that you’ll need to know about battery maintenance. This includes:
Charge cycles will be the number of times that the battery can be fully drained and then fully charged before it needs to be replaced. E-bike batteries can have charge cycles of between 500 and 2,000 times. Obviously, the higher the number of charge cycles, the longer the battery will last.
This will determine how long you need to charge the battery for. On decent e-bikes, it should be around the 5–6-hour mark. However, cheaper e-bike batteries could easily take 12+ hours.
This isn’t something that you’ll need to worry about too much. Not unless you live in areas with extreme heat or cold. All e-bike batteries should be charged at the right temperature. Your user manual will tell you what this is.
The memory effect is something that will impact both NiMH and NiCd batteries. The memory effect means that if you do not fully drain the battery before charging it, the battery will ‘remember’ the point that you started to charge at. Over time, the battery will start to ‘think’ this is the minimum charge level before it is depleted. Do this too often, and you could lose a significant amount of charge capacity on your e-bike’s battery.
Minimum Charge Level
You should never fully drain an e-bike battery. Thankfully, most e-bike controllers won’t let this happen. They’ll tell you the battery is drained before it is. The minimum charge level will depend on the battery tech. Most of the time, this should be around 15-25% of the battery’s overall capacity. Dip below the minimum charge level too often, and you could damage your battery.
Because e-bikes are powered and often travel at some rather high speeds, manufacturers have introduced safety features designed to make the e-bike safer to ride. These are the three main ones.
Regenerative braking has a couple of benefits. The main advantage of regenerative braking is power saving. Regenerative braking takes the kinetic energy of braking and ‘stores’ it. This energy can then be fed back into the motor, ensuring the bike has a larger range.
Regenerative braking can also have a positive impact on safety. Regenerative brakes are quick to engage and can help bring a bike back to a slow speed at a far smoother rate than traditional e-bike brakes.
Some e-bikes come with power cut-off brake levers. These have sensors that, when engaged, will automatically shut the motor off. This can bring the user to a quick stop.
Some e-bikes may also have an automatic motor cut-off if the user stops pedaling. This is required by law in certain countries.
In other cases, the automatic cut-off may indicate that the e-bike’s battery charger will cut off. This can help to protect the battery, while also preventing potential overheating (which can lead to fire).
You’ll need to look at your selected e-bike model to know exactly what type of automatic cut-off it has.
All e-bikes will have a collection of safety sensors that keep tabs on the e-bike. This will help to ensure that the e-bike doesn’t go over a certain speed, that the e-bike slows down when it needs to, etc.
Remember – all this information is just the theoretical side of e-bikes. It is all well and good knowing what the various assist levels on your bike may be labeled as (for example), but it is no substitute for actually playing about with your e-bike. We encourage everybody to experience their e-bike properly. Learn the ins and outs of the assist levels. Look at how your display works. Look at how the bike battery level depletion rate changes depending on your biking route. Every e-bike is different, and you really should understand how your one works.
Once you understand how your e-bike works, you’ll learn how to operate it properly to cycle more efficiently. You’ll learn how to get more battery life out of your e-bike. You’ll learn the exact pedal assist level you need to balance battery life and comfort levels. This isn’t stuff that we can teach you. It is stuff that you need to experience for yourself.