How to Attach Bike Trailer to E-bike : Kids, Pets, and Cargo

As an e-bike rider, you might want to tow your kids, pets, or even your tools and cargo. Using a normal bicycle might be a bit stressful to pull both the bike and a trailer attached behind it. But now, you’ve got an electric bicycle, and you may wonder how to attach a bike trailer to ebike.

To do this, simply find out the measurement of your bike’s hub axle. Then, using a step gear, drill the diameter of the coupler slowly, then at full speed to brush off every imperfection. When you’re done, attach the coupler to the bare axle, fasten the bolt, and you’re good to go!

Note that you need to understand how to attach your bike trailer to your e-bike properly, as any wrong connection can lead to accidents, injuries, and even worse—deaths. But do not worry. In this article, we’ll walk you through the process.

How to Attach Bike Trailer to E-bike

Whether you are using a road bike, cruiser bike, mountain bike, electric bike, disc-brake bicycle, or even a hybrid bicycle, you can attach it to your bike and ride on. Also, using an e-bike to tow anything on a trailer, you can easily ride uphill without feeling the impact of carrying another object.

But, you must ensure to find out the kind of axle your e-bike uses before getting a bike trailer for it. Also, make sure you find out an electric bike that can pull a trailer.

How to Attach Bike Trailer to E-bike

However, learning how to attach bike trailer to ebike can be very confusing. With the different kinds of e-bikes available, you can easily get overwhelmed on how to connect a trailer to an e-bike. So follow the steps below:

Steps in attaching a trailer to an E-bike

Steps in attaching a trailer to an E-bike

1. First of all, expand the coupler

Most trailer couplers come in 10mm axle dimensions, whereas your bike might have a 12mm axle. So get a wrench or crescent wrench, a drill, and a step drill bit.

2. Remove the bolt covering your e-bike’s axle

Loosen the bolt that is covering the e-bike’s axle using a wrench and let the axle remain bare. While drilling your coupler, occasionally check if the couple fits properly with the e-bike’s axle.

Remove the bolt covering your e-bike axle

3. Drill the Coupler

When you are ready to drill the coupler, place it at the edge of a table or workbench- preferably a workbench. After that, place the drill with the step drill in place, and begin drilling the coupler. Reiterate the process until the coupler fits perfectly, not tight or too loose with the e-bike’s axle. Drill it at light pressure and full speed to clean out the rough edges.

4. Return the bolt back in place

While tightening the bolt, use one hand to secure the coupler as you’re screwing the bolt back in place. Then, use your wrench to tighten the bolt until it fastens properly and firmly.

The three types of bike axle

There are three kinds of bike axles you need to know about. They include the quick-release, the classical axle, and the thru-axle. We have looked into them in detail below, and you should check them out.

types of bike axle

1. Quick-Release Axle

The Quick-Release (QR) axle is the most popular type of bike axle, as most bike trailers support the regular quick-release axle bikes. The QR is usually easy to maneuver. However, you might have challenges if you are using a hooded dropout on your trailer. Hooded dropouts may likely need a larger attachment to provide more clearance for connecting the coupler. This also depends on your bike trailer’s brand type.

Quick-Release Axle

For the QR, some companies add a fitting which you can use to reinforce the skewer’s lever cam and make it tighter. Some other companies provide their own dedicated quick-release axle skewer that has its own hitch attachment point integrated with it. If you happen to use a trailer that has its own replacement skewer, ensure that its length is the same as the already-existing QR that you want to replace.

2. Thru-Axle

The Thru-axle skewer is a more recent axle skewer that has gained interest for being stronger and rigid than the quick-release axle. This kind of axle is more popular within modern bikes like road bikes, gravel bikes, mountain bikes, etc. These bikes usually have disc brakes.


The usual length is 12mm in diameter12m, but there are variations in lengths as well. So, ensure to measure the rear thru skewer and compare it with the trailer producer if they provided any replacement axle. That till help you know if you can use the trailer with the e-bike.

3. Classic Axles

If your e-bike has rear hub gears or hub motor, it mostly will have a threaded axle that has nuts that are mooring the wheel. Some hitch attachments easily slip beneath the nut before you connect it. Just ensure that you have enough sufficient threaded axle jutting so you can properly reinforce the nut.

Classic Axles

If you are getting new replacement nuts together with the trailer, we recommend evaluating the diameter by thread pitch measurements of your e-bike axle. In recent times solid hub axles have measurements of 10 mm x 1 mm. However, for older bicycles, you need to re-scrutinize and measure them to confirm if they are 10×1 in measurements.

Types of E-Bike Towing Trailers

There are a few different types of ebike trailers that you might be trying to install on your electric bike: Kids, Pet, and Cargo.

Types of E-Bike Towing Trailers

Kids Trailers

The kids’ trailers come in both the one-seater and the two-seater variations, although you’d regularly see the two-seater variety available. Unfortunately, the one-seater variety is unsafe for children and more dangerous in times of casualties. In addition, it is harder to balance this kind of wheeler.

e bike Kids Trailers

Pet Trailers

The pet trailers enable you to commute your pets around town easily. It comes in different sizes that enable it to carry pets of both large and smaller sizes. In addition, there is an internal leash that helps you secure your pet while riding. One more beautiful thing about this trailer is that a rear door simplifies the exit and entrance to the tent.

e bike Pet Trailers

Cargo Trailers

The cargo trailers come in different shapes and sizes, allowing you to carry variable things, ranging from little tools to bulky loads. In addition, they come in single-wheel or two-wheel varieties.

e bike Cargo Trailers

The single-wheel trailers are more mobile, efficient, and portable but can carry lesser loads. In retrospect, the two-wheel counterparty is more stable and makes it easier to load and offload anything you put in them. However, they are also much heavier and more difficult to tow.

Features to look out for While Considering Attaching a trailer to your E-bike

Here are the things you’ll look for while getting your first electric bike trailer. It’ll help you avoid getting a trailer that doesn’t match your bike size and type:

1. Motor Power

The capacity of your e-bike’s motor will provide more effective results while towing your trailer. E-bikes have up to 1500 watts as their motor’s starting power. While this is effective for riders who don’t use trailers, it’s not very efficient for those who do and ride in hilly terrains.

Having a motor power of 500 watts or more is more suitable for riding hilly areas seamlessly. Also, if you are towing your trailer, we recommend you choose a motor that is one step above your regular motor power on your weight and terrain—without attaching a trailer.

E-bike Motor Power

For example, in your regular weight and terrain, you will need a 350 watts motor without using a trailer. However, when you use a trailer in that same weight and terrain, you will need a 500 watts motor. Also, note that several states place restrictions on e-bikes between 500 and 750 watts max without needing a speed license. Thus, ensure to find out regulations within your state to avoid breaking the law.

2. Type of E-bike Motor

Another thing you should understand is the type of e-bike motor your bike has. The motor can either be mounted between the front hub, the rear hub, or the mid-drive motors. At the front hub, you will find the motor on the wheel; at the back, it is on the bike’s back wheel. Whereas, at the mid-drive, it is in-between the bike’s motors and on the bicycle’s crank.

3. Battery Capacity

As we all already know, when it comes to e-bike batteries—the bigger, the better. Bigger batteries will last longer and can also supply a larger amount of power to the circuit. In addition, the battery capacity should be proportional to the amount of load the bike will carry.

4. Brake Capacity

Your e-bike braking system should also be at the top of your consideration. Reinforcing your e-bike with disc brakes gives you a more effective braking power. Disc brakes are also very effective when carrying heavy loads and under rainy conditions.

How Much Weight Can An Electric Bike Pull?

How Much Weight Can An Electric Bike Pull

When Towing Children

Noting that e-bike trailers are very effective in towing kids, we need to know just how much they can carry along. In truth, it depends on some factors, such as the terrain and the weight of the child.

Open trailers are suitable for carrying children above six years old. They come with versatile suspensions, which can absorb impacts from road bumps. In contrast, the enclosed trailer is ideal for younger children below six years. It has waterproof roofing that offers protection from rain and that can be removed if the weather becomes too hot. The kid’s trailer can tow a total of 110lbs.

When Towing Pets

Trailers for pets vary in shape and size. Thus, they’re able to carry heavier weights than trailers for kids. Typically, the trailers for pets can sustain a weight of over 275lbs. (or 125 kg).

When Towing Cargo

Cargo trailers are usually built to carry heavy weight for a longer distance. Thus, you can see cargo trailers that can carry up to 300lbs.

Bottom Line

The towing trailers are effective in carrying your children, pets, and luggage around with you. Even though many people know the benefits, the challenge often comes on how to attach bike trailers to ebike

To attach a bike trailer to an e-bike, you need to know how to fasten the coupler properly within the e-bike’s axle—noting the essential parts and using the right tools. If the bike’s axle has a bigger dimension than the trailer’s coupler, you should use a drill and step drill to enlarge the hole. Only ensure that the coupler’s hole is not too wide for the bike’s axle diameter.

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