Can electric bikes pull trailers? Even uphills?


I wanted to buy an electric bike for my wife’s birthday so she could take the kids to school in a trailer, but I wasn’t sure if an electric bike could pull a trailer uphills. 

Since we live on a steep hill it was an important issue for me. 

I searched for articles on the Internet, forums, and I asked the guy at my local bike shop, but I couldn’t find a definitive answer…

I bought one anyway to find it out.

Here is the result of my research combined with my experience with our electric bike.

Can an electric bike pull a trailer?

Electric bikes can pull trailers, which makes them a convenient option for bike commuting with children and grocery shopping. Some electric bikes are strong enough to pull trailers uphills, even on steeper climbs with relatively heavy loads. To understand whether an e-bike is up to the task, you need to consider a few things before buying one.

In this post I will explain what kind of an e-bike you need to pull your trailer and the best trailers available for your electric bike.

The electric bike

In order to understand whether an electric bike can pull a trailer, you need to consider the following factors: 

  • Type of electric motor
  • Amount of extra weight
  • Terrain
  • Power of electric motor

Type of motor: Hub vs mid-drive

Whether buying a hub or mid-drive motor e-bike is probably the most important decision. They both have their advantages and limitations.

Electric motors take energy from your battery and give you torque in return. 

Hub motor

A hub motor, gives you torque directly at the wheel, and the gears on your bike don’t come into play. Some electric bikes have their hub motor built into the front wheel, but more commonly they have it built into the rear wheel. 

The main advantage of hub motors is that by design they can be used in power-on-demand mode, which is a fully automatic mode. You don’t need to pedal to move forward. This makes them very convenient. E-bikes with hub motors can also be used  in pedal-assist mode.

The power-on-demand mode advantage of hub motors only applies in certain countries though. Some countries, such as the EU countries, don’t allow e-bikes with a throttle.

The biggest limitation of hub motor electric bikes is that even if you change gear you will get the same amount of power assistance from the motor. This is why it’s important to choose an e-bike with sufficient motor power if you go down the hub motor route. You need a 750W motor to match the power you can get from a 250W mid-drive motor when in the lowest gear.

An electric bike with a 250W hub motor can pull a trailer on a flat surface, but it will struggle to ride uphill. If you want to buy an electric bike with a hub motor, you should look for something around 750W. It will be strong enough to do the job.

Mid-drive

A mid-drive motor gives you torque at the pedal, and the power gets transferred through the chain and cogs to the wheel. 

The genius of mid-drive motors is that by changing to a lower gear you can multiply the torque of the motor. 

A bike with a 250W mid-drive electric motor is strong enough to assist you up a steep hill with a full trailer. You need to switch to the lowest gear on your bike and you need to pedal harder than normal, but it makes getting up the hill possible.

I ended up buying a mid-motor e-bike for my wife, because I figured that it had the added benefit of the gearing. I once raced her uphills on a steep, 10% gradient (that’s pretty steep!!).

She had the electric bike I’d just bought her, a trailer with two children. The total extra weight she had was of 120lbs (55 kg). I was on my road bike with no additional weight. 

She killed me on the 0.5 mile (0.8 km) climb, and got to the top of the hill almost a minute before me. Not even to mention that by the time I got to the top of the hill I was spitting my lungs out. She was panting, but still breathing normal.

The limitation of mid-drive motors is that they can only assist you when you pedal, and they are not available in power-on-demand (aka throttle) mode. You still need to do some pedaling to get the motor to work for you.

Extra weight

The more extra weight you pull the more extra power you need to keep you going.

A bike trailer weighs between 30-45 lbs (14-20 kg) on average, and it can carry up to 50 – 275 lbs (23 – 125 kg).

You should calculate the amount of extra weight you will be pulling by adding the intended load to your trailer’s weight.

Here are some examples of how much extra total weight you need to consider (in addition to the bike and the rider):

  • Small trailer + groceries for a week for a small family: 50-55 lbs (22 – 25 kg)
  • Small trailer + 4-year-old child: 65-75 lbs (30 – 34 kg)
  • Large trailer + groceries for a week for a large family: 90 – 100 lbs (40 – 45 kg)
  • Large trailer + 2 children (3&5 years old): 120 – 140 lbs (55 – 64 kg)

If your total extra weight is less than 75 lbs (34 kg), and the intended use is on flat terrain then you will be happy with any electric bike. You will get enough assistance, but some bikes with weaker hub motors may struggle to get you up to the maximum speed they are capable of when traveling without the trailer.

If your total extra weight is more than 75lbs, then smaller hub motors (250W hub motors) will be too weak to move the vehicle, and you need to consider one of the following options:

  1. 250W mid-drive motor
  2. 500-750W hub motor

Because of the 250W upper power limit on electric bikes in certain countries, if you live in one of these regions and you want to pull over 75 lbs, you need to look for an electric bike with a mid-drive motor.

If you’re in the US (most parts of the US anyway) or in a country where the limit is higher, you can opt for a 750W hub motor.

Terrain

The terrain makes a huge difference whether or not you have a trailer. Even a slight incline slows you down. When you have a trailer it’s always extra work, because of the added weight. 

If your neighborhood is relatively flat, there are no long distances to cover and speed doesn’t matter, then any type of electric bike is sufficient. Even basic electric bikes will serve you fine.

However, if there is any hill, especially if it is somewhat steep, weaker electric bikes with hub motors will struggle and won’t provide enough assistance. Also, if being able to keep a steady speed is important, or if you want to ride longer distances, you will need to look for something a little more advanced.

Motor power regulations

If you have a heavy trailer to pull, buying the most powerful electric bike available is not the answer.

You can buy ebike conversion kits of 1500W (and even more powerful ones) online, but there are some rules that restrict the use of electric bikes in each country, which disqualifies 1500W e-bikes from the bicycle category.

If your e-bike doesn’t meet certain requirements, it’s no longer considered a bicycle and it’s not allowed to use bike lanes, cycle paths and enjoy all the privileges of a bicycle on the road.

Let’s go through the classifications to get a general understanding. I still recommend that you find out the restrictions that apply in your region in greater detail, but this gives you a broad overview.

In the US, electric bikes are divided into three categories: 

  • Class 1: Pedal assist bikes only, with a maximum motor power of 750W. These bikes can assist up to 20 mph (32 km/h). These bikes can have mid-drive or hub motors.
  • Class 2: Bikes that can operate in a pedal-assist mode as well as in power-on-demand mode, with a maximum motor power 750W and a maximum speed of 20 mph (32 km/h). They only come with hub motors.
  • Class 3: These bikes can assist the rider up to 28 mph (45 km/h) when pedaling. Some of them have a throttle-mode up to 20 mph (32 km/h). The maximum power is still limited in 750W. In some regions, there are restrictions in place for class 3 e-bikes.

In Europe and some other countries, electric bikes fall into two categories:

  • Pedelec: Bikes with pedal-assist mode only, with a maximum power of 250W and a maximum speed of 15.5 mph (25 km/h). They are available with both mid-drive motors and hub motors.
  • S-Pedelec: Bikes with pedal-assist mode only with a maximum power of 750W and a maximum speed of 28 mph (45 km/h). These bikes are not considered bicycles, and they are not allowed to use bike lanes, may need insurance, mandatory lights and can only be ridden with a helmet. Other restrictions may apply too. 

Some countries are very strict in enforcing the law, so you need to do your due diligence to know what rules apply in your country.

Here is a quick summary of the categories in a table:

Battery life when pulling a trailer

Riding an e-bike with a trailer reduces the bike’s battery range. 

How fast your battery will be depleted compared to when it’s not pulling a trailer depends on:

  • The level of assistance
  • Extra weight
  • Terrain

Weight and terrain don’t only play an important role in deciding what type of motor you need to opt for. They influence a great deal how far you can go on a single charge too.

Besides weight and terrain, the level of assistance is the third important factor in your battery range. Your leg is a “motor” too, because the harder you’re able to pedal the less the motor needs to work. This means that you get longer range out of each charge. 

Using an electric bike in power-on-demand mode with a heavy trailer reduces its maximum range by up to 80%. This means that if your e-bike is capable of doing up to 50 miles (80 km) on a single charge, you may only get 10 miles (16 km) when fully loaded and on a hilly terrain.

If you use your bike in pedelec mode (it only assists you when you pedal), the motor doesn’t need to work as hard, so you increase your e-bike range. 

By lowering the level of assistance and pedal more, you can go further on a single charge. 

My experience is that a fully loaded electric bike on a mixed hilly and flat terrain gives 30% of its maximum range. Our electric bike is rated at 125 miles (200 km) on the lowest assist level on flat terrain, but on the highest assist level, towing a fully loaded trailer on a mixed hilly and flat terrain we only get about 37 miles (60 km) out of one charge. 

Trailer recommendations

If you already have an electric bike, and you’re confident that it’s up to the task you need it for, then you need to pick a good trailer. 

There are three categories of bike trailers: cargo, pet and child trailers. 

Cargo bike trailers

Cargo bike trailers are designed to carry heavy weights over long distances. They come in various sizes. Since their platform is not divided into smaller spaces for seats and luggage, they are perfect for grocery shopping, and odd-shaped items.

If you only need a trailer for groceries, the Schwinn DayTripper Cargo Bike Trailer (available on Amazon) is a good choice. It’s lightweight, and provides plenty of room for your weekly shopping. It can carry up to 100lbs (45 kg), and you can fold it for easy storage when it’s not in use. 

If you want to carry larger, heavier items such as buckets of paint, lumber, you need a heavy duty cargo trailer. Check out the Cycle Force Trail-Monster Cargo Trailer (find it on Amazon here), which is built like a tank. It can carry up to 275lbs (125 kg) of weight, which is more than most e-bikes can pull.

Pet bike trailers make it easy to safely transport your dog, cat or other pet. The Schwinn Rascal Tow-Behind Bike Pet Trailer (click to check price on Amazon) is large enough to carry a pet that weighs up to 50 lbs (23 kg) and it has a larger version too, which can carry up to 100 lbs (46 kg). It comes with an internal leash which gives you the peace of mind that your pet can’t jump out whilst riding. It has a rear door for easy entrance and exit, and it has an adjustable bug screen as well as a weather shield that protects against rain.

When not in use, the wheels can be taken off easily and the trailer can be stored flat. It’s perfect if you have little storage space, or if you want to take it with you in the car.

Child bike trailers are specifically designed to carry children. They come with straps installed so your child travels in safety. 

I carry my children in our trailer all the time and they love it. They can play inside and it also has see-through walls so they can look around. In my experience, children can get tired or bored in the trailer after a while, which is why I prepare some toys or books for them.

For an entry level trailer, which can carry two children up to 40 lbs (18 kg) each, I recommend the InStep trailer (available on Amazon), which has made plenty of families happy. It is perfect for the occasional school run or weekend ride. It also has a trunk so you can carry your bag or a picnic lunch.

For heavy duty, regular users, who want to use the trailer as a stroller or even as a cargo trailer, the Burley Encore X (available on Amazon) is a very appealing option. It is one of the safest and most comfortable bike trailers available on the market and it pays attention to every practical detail for both the rider and the children aboard. It folds flat for easy storage or transportation. It can carry up to 100 lbs (46 kg) of weight, so it’s suitable for a bigger and a smaller child with some extra luggage aboard.

For heavy duty, regular users, who want to use the trailer as a stroller or even as a cargo trailer, the Burley Encore X (check price on Amazon) is a very appealing option. It is one of the safest and most comfortable bike trailers available on the market and it pays attention to every practical detail for both the rider and the children aboard. It folds flat for easy storage or transportation. It can carry up to 100 lbs (46 kg) of weight, so it’s suitable for a bigger and a smaller child with some extra luggage aboard.

Conclusion

E-bikes and trailers are a great combination. If you love cycling, it’s a combo that can replace a car in the family. As long as you set realistic expectations, don’t overload your trailer and have a bike with sufficient power, you will be a happy rider.

Happy Riding!

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