How much power does my electric bike need?

How much power does my electric bike need?

Here’s a question you should ask yourself when shopping for an e-bike. Power can be one of the main considerations when deciding which e-bike you choose. When talking about the power of an e-bike, you are referring to the power of its motor, measured in watts.

The amount of power an e-bike needs depends on your usage. The harsher the conditions you will be riding, the more power you will need. Demanding riding situations can include carrying heavy loads, riding steep hills, and being a heavy cyclist.

When shopping for an e-bike, you need an e-bike that’s powerful enough to meet your needs while still staying within your budget. The power of an e-bike motor is usually any of the following wattages.

250W, 350W, 500W, 750W or 1000W.

I will discuss each of the above motor power wattages in this article. What kind of performance and suitable use are covered, you can expect from each. This is to help you decide which is best for you. But first, there are a few factors you can consider when deciding on an e-bike’s power motor.

Disadvantages of increasing power

A high-powered motor on an e-bike isn’t always better. This is because of the following 2 factors.

cost
The more powerful the motor, the more the electric bike will cost. At least in general. I say generally because other factors like build quality and motor type also affect cost.

If the motor is powerful enough for your needs, you may not see the need to pay extra for a more powerful motor. You may find that a 250 or 350 watt motor is powerful enough for the cycle you intend to do.

Battery
Battery efficiency also needs to be considered. The more power the motor uses, the more battery is needed to travel the same distance, as with a lower power motor. This reduces battery range. So, as a general rule of thumb, higher power motors require larger batteries. This means extra weight on your bike, and further added cost. As you know, bigger batteries mean higher prices.

electric bike battery

Legal requirements
You need to consider the legal requirements of the country or state where you live (if you are in the US).

Different countries and U.S. states have different legal restrictions on the power motors that can be used on e-bikes.

There are legal limits on motor power, allowing countries and U.S. states to determine what an e-bike is. Any e-bike with a motor power above the legal limit is considered a motor vehicle. In this case, you will need the applicable licenses, insurance, taxes, etc.

There’s also the safety aspect. You must not drive/drive a motor vehicle where it will endanger the safety of people, such as on public roads.

In the US, most states currently have a legal power limit of 750 watts for e-bikes. But this is different in some other states. In the EU, UK and Japan it is 250 watts. Canada is limited to 500 watts and China is limited to 400 watts.

Ultimately, your e-bike shouldn’t have more power than is required by law where you live, or at least where you currently live.

250 watt motor

This is the entry-level power you’ll find for an e-bike.

For general road use, and if you don’t anticipate riding your bike on many steep hills (if any), or if you’re not a heavy rider, this may be a suitable option. Especially if you’re looking for that extra boost without paying for more power than you need.

cyclists in town

Here are some scenarios where you may find the extra boost beneficial without going all out.

If you want to stay active on your commute but want to get there fast without breaking a sweat.
You may enjoy long leisurely outings, such as pleasant rides in the countryside. Electric assist may be the extra help you need to get you farther than usual. It might give you more confidence to run a few extra miles, knowing that if you get tired, the motor will take you home.
If you are recovering from an injury or illness, are currently lacking in health, or suffer from a condition such as arthritis, extra help can be your starting point for cycling.
You may have been cycling with your friends or buddies a lot, or even with a cycling group, but fell behind. Here, a little extra power can help you keep up.
If you live in a hilly part of the world, a 250-watt motor might not be the best choice for you. Whenever you hit a steep hill, especially if you are a heavier rider, you will slow down with this power.

If you’re a moderate weight and in good physical condition, 250 watts is more than enough power for steep hills. If you just need a little help to supplement your own pedaling power, that’s more. But if you want to raze those hills to the ground, then you want to look at more power.

350 watt motor

Here we have a slight power boost compared to the 250 watt motor. A 350-watt motor is a valid option, even if you want a 250-watt motor to be enough for your needs. This is because you can be sure to have some extra power in case you need it. You’re still not here to fork a super-powerful e-bike.

If you go for an e-bike with a throttle, I’d say that’s the minimum recommended power level. If you’re only using the throttle on hilly terrain, the 250-watt motor probably won’t cut it well enough. That’s because when you’re only using the gas pedal, you’re not pedaling to supplement the motor’s power. Here, the motor is doing all the work.

If you plan to use your e-bike to transport cargo, you can attach a trailer or opt for a dedicated cargo e-bike. The extra power you get from this motor is the most welcome. However, if you carry a lot of cargo, it may be better to opt for a more powerful motor.

500 watt motor

You will usually find that 500 watts is more than enough for the average person. Even if you’re a moderate-weight rider, you should still find this power plenty when you’re climbing steep hills or carrying heavier loads. Anything beyond that is probably overkill.

cargo bike graphics

If you are a heavier rider, you can still find this power enough to get you up tough hills. To help you further, though, if you’re a heavier rider, you can make sure your motor is mid-drive. The motor on an e-bike can be a mid-drive motor or a hub motor. The mid drive motor is the more efficient motor of the 2. They will help you more on steep hills and rough terrain. Besides wattage, this is a further consideration when it comes to choosing a motor that will give you the help you need.

Compared to in-wheel motors, mid-drive motors are more expensive but more battery efficient. So, keep in mind that the higher the wattage of the motor, the more power it can usually draw from the battery. Means bigger, more expensive batteries. You may find that opting for an e-bike with a 500-watt mid-drive motor has more than enough power for your needs. It’s a more cost-effective/battery-efficient option than an e-bike with a 750 watt hub motor.

Ultimately, choosing a mid-drive motor over a hub-drive motor reduces the need for more power. This is also useful if 500 watts is the legal limit where you live.

750 watt motor

You may want to cover your base if say you are a heavier rider expecting to climb a lot of rough hills and terrain and/or you are carrying heavy cargo. In this case, this power should be enough.

Again, you can further maximize help by making sure the motor is an intermediate drive. Keep in mind that this will add cost. The increased battery efficiency of the mid-drive motor will help mitigate the extra drain on the battery due to the large amount of power you get. As mentioned earlier, in many states in the US, the legal power for e-bike motors is 750 watts.

man riding electric bike uphill

If you’re only riding on flat slopes, with a moderate weight and not carrying much cargo, this power will be excessive. In these cases, there is no extra charge for this motor and a larger battery (which may be required).

Having said that. Depending on how much money you’re prepared to invest, you may want to have that much available power. It will come in handy one day, even if you don’t need it most of the time. For example, if you’re going on a cycling vacation, take a long ride in the mountains.

750 watts won’t give you a noticeable difference in performance on the flats compared to a less powerful motor. In addition to the increased acceleration obtained from a resting position. This can get you out of dangerous situations, such as busy intersections.

However, be careful if you’re riding an e-bike with a 750-watt motor. This high power and acceleration can make you more prone to accidents. Especially when riding in urban areas where there are many potential dangers. With great power comes great responsibility!

1000 watt motor

This is all out. With that much power, you actually get some pretty impressive hill climbing abilities.

In many, if not most, countries around the world, e-bikes of this power are too powerful to be legally classified as e-bikes. This means they will be classified as motor vehicles. Here you will be limited to where you can ride them and will need applicable permits and taxes etc.

Cyclist rides electric bike on mountain

You would expect a higher price for an e-bike of this power. Most people don’t need that much power anyway, though. If you plan to use your e-bike to haul heavy loads and/or live in the mountains of the world, you might appreciate this level of power.

If you choose a 1000-watt e-bike, keep an eye on the battery level as you ride. You’ll need a bigger battery to get decent range, which adds weight to the bike.

In conclusion

Overall, it doesn’t hurt to buy an e-bike with the most powerful motor possible. That is, as long as it’s within the legal limits of where you live and you can ride it safely. As mentioned, even if you don’t currently need all the power the motor provides, it’s good to know it’s always available. You never know when it will come in handy.

Keep in mind that the more powerful the motor, the more battery power it tends to drain for the same distance from a lower powered motor. If you’re prepared to pay extra for a bigger battery to get around this, this probably isn’t an issue. After all, a little careful battery management can help you get the most out of your battery. In any case, you don’t always need to utilize all of the motor’s power while riding.

It’s good to know that if you’re on a tight budget and don’t need to go all out, you can still find an affordable e-bike that fits your needs. It doesn’t take an all-out effort to help you narrow down the range of e-bikes you want. This might help, as the range to choose from is so large that it can be overwhelming.

On the budget side, you may find that compromising on motor power may make other features of an e-bike affordable. For example, you might want your e-bike to be fully suspended. Opting for a 500-watt motor, rather than a 750-watt motor, might be more affordable for you. If 500 watts is still powerful enough for you, this would be an ideal solution.