Complete Guide: How to Attach a Bike Trailer to Any Bike [With Photos & Videos]

​May 30, 2022

​Follow this guide to attach a bike trailer to any bike safely. Learn the difference in hooking up a bike trailer to a quick-release, bolt-on, or thru axle.

Complete Guide: How to Attach a Bike Trailer to Any Bike [With Photos & Videos]

No matter what kind of bike you have, there’s almost certainly a way to attach a bike trailer to it!

For the most part, bicycle trailer brands and models can be attached to bikes in a similar way. It's usually a simple and quick process. When you've attached your trailer to your bike once, it becomes significantly easier each time after that ‒ just like riding a bike!

Here, we aim to provide the most comprehensive, illustrated guide on how to attach a bike trailer to any bike, even if you’ve lost the instruction manual (or the manual is so confusing that it has you lost!)

I'm sure you're eager to get started, so let's get right into it!

What You NEED to Check Before Attaching Any Bike Trailer to Any Bike

No matter what brand or model of bike trailer you choose, there are two key things to consider before you attach it to your bike.

You will want to know:

1. The type of rear wheel axle on your bike
2. Whether your bike has a hooded dropout

Don’t worry, we'll explain what these mean and how to go about checking in the next sections. Once you know, you'll be able to attach a trailer to your bike with confidence!

1. How to Identify the Type of Rear Wheel Axle on Your Bike

A wheel axle is a threaded metal rod that attaches the wheel to the bike while allowing the wheel to spin. The threads are there so that the axle bolts and bearing crown races can be screwed on to secure the axle.

Your bike has two wheel axles ‒ one for the front wheel and one for the rear ‒ but today we're just looking at the rear wheel.

There are three main kinds of wheel axles, and the difference is important when it comes to how to attach a bike trailer to your bike: quick-release axles, bolt-on axles, and thru axles.

1. Quick-release axles are the most common type of bike axle today. A quick-release axle is clamped in place by a lever on one end, with a nut securing it on the other end. A threaded skewer passes inside the hollow axle and tightens the hollow axle to the frame.
2. Bolt-on axles are different from quick-release axles in that they are solid instead of hollow, and are secured on both ends by nuts. There is not quick-release lever.
3. Thru axles are seen on newer bikes with disc brakes, especially mountain bikes. These axles are thicker than other axles, passing through the wheel hub and threading directly into the frame.

With a quick-release axle, you shouldn't have any problems attaching almost any bike trailer to your bike. But the skewer must be long enough to accommodate the additional thickness of the bike hitch. The skewer nut should engage the skewer with 5 complete thread. If it does not then you will need to purchase a longer skewer from your local bike shop. If your bike has hooded dropouts you may require a spacer to give more room for a bike trailer hitch - but I'll talk more about hooded dropouts later.

Most bike trailers are designed for quick-release axles, but many of them can also be attached to bolt-on axles with the right tools. You just need to be able to loosen the left side nut to attach the bike trailer hitch.

Thru-axles that are at 12 mm or thicker in diameter are usually too big to fit through a bike trailer hitch’s attachment hole, so you'll need an adapter.

2. How to Identify the Type of Dropout on Your Bike

The dropouts are the two slots through which the wheel axle is attached to your bike frame. While there are many different types of dropouts, we can group them into two general categories:

1. Standard dropouts have a flat area around and below the axle where the bike trailer hitch or couple can sit flush against the frame. You’ll find this style of dropout on most bicycles.
2. Hooded dropouts feature a metal hood that sticks out a bit from the top of the dropout over the axle hole. For bike trailers with hooded dropouts, spacers will be needed to create the clearance you need to attach the bike trailer hitch or coupler.

Chances are your bike will have standard dropouts that will give you no trouble when it comes to attaching a bike trailer to your bike. If your bike has hooded dropouts, you’ll need to talk to the manufacturer of your bike trailer to find out whether they offer spacers that you can use.

How to Attach a Bike Trailer to Your Bike ‒ 3 Ways

What You’ll Need

Most bike trailers come equipped with the following key components you’ll need to attach the trailer to your bike.

• Tow bar/tow arm

• Tow bar bracket

• Bike trailer hitch/coupler

• Hitch/coupler pins

• Safety strap

In most cases this is all you will need to safely connect the trailer to your bike, unless you’re dealing with a thru axle, which likely requires a special adapter.

Getting Started

As a first step to attaching a bike trailer to your bike, you'll need to set up the bike trailer hitch or coupler so it can attach to your bicycle. These steps apply to Wike bike trailers and bike axle/dropout:

1. Insert the tow bar pin in the foremost hole on the left side of the trailer. Be sure the tow bar is in the correct position and the holes are aligned on the tow bar and the frame.
2. Lock the tow bar with the tab lock pin on the side, then secure with the hairpin inside the trailer.
3. Locate the tow bar into the bike trailer hitch/coupler and lock it in place with the pin. Then, lock the pin in place. Then wrap the safety strap around the bike frame and clip it back to the towbar.

Once you are ready, move on to the next section based on the type of axle you are dealing with:

1. How to Attach a Bike Trailer to a Bike with a Quick-Release Axle
2. How to Attach a Bike Trailer to a Bike with a Bolt-On Axle
3. How to Attach a Bike Trailer to a Bike with a Thru Axle

a. How to Attach a Bike Trailer to a Bike with a Quick-Release Axle

Watch a video demonstration: Connecting your Bicycle Trailer: Quick Release

1. Remove the quick-release skewer.[OM1]
   1. Flip the quick-release lever of the rear wheel axle and loosen the nut on the opposite end to loosen the quick-release skewer.
   2. Slide the skewer out from the axle. Don’t lose the nut, spring or lever!
   3. Thread the skewer through the bike trailer hitch/coupler so that the hitch/coupler is on the left side of the bicycle.

1. Replace the quick-release skewer with the hitch attached.
   1. Slide the skewer back through the axle. The hitch/coupler should sit flush against the dropout on the left or lever side.
   2. Replace the spring and nut on the opposite end of the skewer and tighten into place.
   3. Adjust the nut to produce the proper resistance while rotating the quick-release forward.

1. Attach the tow bar.
   1. Line up the tow bar and insert the pin to lock it in place.
   2. Align the trailer hitch/coupler horizontally and close the quick release lever. Depending on the geometry of your bike, you may need to adjust the hitch/coupler so that the tow bar correctly aligns.
   3. Wrap the safety strap around the bike frame and lock it in place.

Good news! You'll only need to do this once. Since the bike trailer hitch is small and light, there's no need to remove it when you’re riding without a bike trailer. You won’t even notice it’s there.

b. How to Attach a Bike Trailer to a Bike with a Bolt-On Axle

Watch a video demonstration: Connecting your Bicycle Trailer: Bolt-on Hub

A bike trailer can be attached to a bolt-on axle similarly to a quick-release, so the images above can serve as a helpful reference in addition to the video demonstration.

1. Remove the axle.
   1. Loosen the nut and washer (if there is one) of the rear wheel axle on the left side of the bicycle.

1. Replace the quick-release skewer with the hitch attached.
   1. Place the hitch/coupler onto the axle and replace the washer and wheel nut. The hitch/coupler should sit flush against the dropout on the left or lever side.
   2. Tighten the nut just enough to allow you to adjust the alignment of the hitch/coupler.

1. Attach the tow bar.
   1. Line up the tow bar and insert the pin from the bottom to lock it in place.
   2. With the hitch in correct alignment, tighten the rear axle nut while keeping the hitch in position. If there is no way to keep it from rotating, disconnect the tow bar and align the hitch so that the final tightening of the axle nut rotates the hitch into the correct position as it tightens.
   3. Wrap the safety strap around the bike frame and lock it in place.

You won't need to remove the hitch when you're not towing a bike trailer because it is small and light. The hitch won't interfere with your regular riding at all!

c. How to Attach a Bike Trailer to a Bike with a Thru Axle

Thru axles bigger than 12 mm in diameter will usually not fit through the hole of the hitch that comes with your bike trailer.

To attach a bike trailer to a bike with a thru axle, you’ll need to purchase a thru axle adapter that is correctly sized for the axle and dropouts. To find the right fit, you’ll need to know the diameter, length, and thread pitch of your thru axle. You’ll find this info in the user manual that came with your bike or remove the thru-axle from your bike’s wheel and check the numbers printed on its side. Following that, you can also try looking up your bike with this bike axle identification tool.

Bike Trailer Attachment Safety Tips

Any good bike trailer is designed with failsafe's to keep it attached to your bike at all times. Here are a few small but important safety tips to follow when hooking up your bike trailer and hitting the road!

Safety Tip 1: Check the Hitch Before Each Ride At First

Check your hitch before each use and during long trips until you are confident of how it operates and how to use it. Use your trailer only if you are sure of how to use the hitch.

Safety Tip 2: Replace the Hitch Every 3 Years

At Wike, we recommend replacing your bike trailer hitch once every 3 years, or whenever it shows clear signs of wear and tear. Our replacement bike trailer hitch will only run you around $20. A small expense that helps ensure your safety and the safety of your passengers!

Safety Tip 3: Always Use a Secondary Safety Strap

All bike trailers should be equipped with a safety strap. No exceptions! In the rare event your bike trailer hitch fails, this accessory can literally save a life by keeping the trailer attached to your bike long enough that you can come to a safe stop.

Still Not Sure How to Attach a Bike Trailer to Your Bike?

Although the instructions above apply to most bike trailers, we cannot guarantee that all bike trailer models will work in the same way. If you have questions about how to set up your bike trailer, you should contact the manufacturer. If you have a Wike, that’s us! Contact us by email or call us and we’ll be happy to help you get up and running.