Qeridoo magazine

Attach bicycle trailer to e-bike: info on axle, coupling & co.

Would you like to attach a bicycle trailer to your e-bike? There are various axle and coupling systems that differ depending on bicycle type and intended use. Here we present the most common options so you can find the right solution.

Author Wilhelm Wenzel

Wilhelm Wenzel

Head of development department

The key points in brief

Attach bicycle trailer and coupling to e-bike

You can attach your bicycle trailer at different points on the e-bike. The most common variant is the rear axle, but it can (depending on brand) also be mounted on the saddle or on the frame .

For the trailer to be hitched to the rear axle of the e-bike, an intermediate piece – the coupling – must be mounted. How exactly this works depends on the type of axle. There are axles with quick-release, thru-axles or full axles.

Here is an overview of the most common coupling systems and axles for bicycle trailers:


 Axle coupling:
  • Attachment under the saddle
  • Quick and easy to mount
  • Suitable for lighter trailers
 Seatpost coupling:
  • Attachment under the saddle
  • Quick and easy to mount
  • Suitable for lighter trailers
 Frame coupling:
  • Bicycle trailer attachment to the frame, often on the chainstay
  • Requires drilling in the frame
  • Suitable for e-bikes with corresponding attachment points
 Quick-release axle:
  • Quick-mount axle with quick-release lever and springs
  • Common on standard bikes without special axles
 Thru-axle:
  • Modern axle, often requires adapter and torque wrench
  • Suitable for modern e-bikes and mountain bikes
Before you buy

What should I look for when buying a bicycle coupler and trailer?

Before buying an e-bike and bicycle trailer there are a few important points to keep in mind so that your child travels safely. First you should check the manufacturer's approval, since not all bicycles are suitable for trailers .

Carbon frames in particular can break under the additional load. So make sure your bicycle offers the stability needed for towing a trailer.

Frau am Fahrrad mit Qeridoo Fahrradanhänger
First check whether your bicycle is designed to tow a trailer.

Important:

Trailers must comply with DIN standard EN 15918 in order to ensure safety standards such as coupler stability and spoke protection.

Also pay attention to the weight limits of your e-bike and the bicycle trailer. Do not exceed either the maximum towing load or the permissible total load of the bicycle, in order to ensure safety while riding. Tip: When transporting a baby, the right baby insert in the bicycle trailer is crucial for your child's comfort during the ride. With a seat reducer, a baby shell or hammock even newborns can be transported in the bicycle trailer.

Mounting

Where is a bicycle trailer mounted on the e-bike?

In most cases the bicycle trailer is attached to the rear axle of the bike . There are various types of axles, which are presented in the following. After you have determined the axle type of your e-bike , you can then mount the matching bicycle trailer coupling.

Good to know: There are also other attachment points for the bicycle trailer that require other couplings. These are for example the seatpost coupling (attached under the saddle ) or frame coupling (mounted with drilled holes or at corresponding attachment points on the bike frame).

Axles on the e-bike

Bicycle trailer coupling: mounting depending on axle type

Each axle requires specific attachment methods for your bicycle trailer. The axle type determines which coupling is suitable and how it must be mounted.

Mount the Qeridoo bicycle trailer coupling
Before you can mount the bicycle trailer, you should determine your bike's axle.

The rear axle is particularly well suited for mounting a trailer, since thanks to its low center of gravity it offers high stability during the ride. Important: The bicycle trailer is always mounted on the left in the direction of travel. This ensures sufficient distance to the chain and the derailleur.

Bicycle trailer attachment with quick-release

The quick-release is a common type of attachment, which is particularly suitable for mounting bicycle trailers.

1. Open the quick-release:
Open the lever to release the axle. The quick-release has two small springs at the ends and an axle diameter of about 5 mm.

2. Mount the coupling:
Slide the coupling adapter onto the axle and place the coupling at the desired position. Tighten the screw bolts hand-tight to create a stable connection.

3. Fix:
Close the lever until it sits tight. Make sure not to close it with force, so no damage occurs.

4. With insufficient threading:
If the thread is too short, you can use a longer quick-release axle. Remove the old axle and replace it. Make sure not to lose the springs .

Image bicycle quick-release
With this system you can attach your bicycle trailer coupling to the quick-release simply and securely.

Attach bicycle trailer to thru-axle

Attaching the bicycle trailer to a thru-axle requires precise dimensions and often an adapter. Here's how to proceed:

1. Prepare mounting:
Check whether your thru-axle has the required diameter of at least 9 mm and a thread on one side.

2. Use adapter:
In many cases the thru-axle requires an adapter to correctly mount the coupling. Make sure the adapter is compatible with your e-bike.

3. Use torque wrench:
Mount the coupling according to manufacturer specifications and tighten it with a torque wrench. This ensures the correct tightening force and stabilizes the mount.

4. Adjustment and fixation:
Make sure the coupling is correctly aligned and securely attached to ensure a smooth ride.


Attach bicycle trailer to full axle

Attachment to a full axle is particularly relevant for older bikes and less for e-bikes. Here's how to proceed:

1. Check the axle:
Make sure that enough thread is available for the coupling (at least 15 mm). Full axles are typically recognizable by cap nut attachments and cannot be removed.

2. Use adapter:
If the thread is too short , an adapter may be necessary, e.g. a 3.8 mm or 5 mm thick axle adapter. This ensures that the coupling can be safely mounted .

3. Ensure stability:
Make sure the coupling sits tight and check that no parts feel loose.

Tip: A polygon adapter can help make different axle and coupling systems compatible with each other . It is particularly helpful if your e-bike has a special axle that is not directly suitable for trailer mounting .
Coupling systems

Attach bicycle trailer to e-bike: various coupling systems

When attaching a bicycle trailer to the e-bike, there are various options that depend on the axle and the e-bike model.

Axle coupling: connect bicycle trailer

The axle coupling is mounted directly to the rear-wheel axle or the frame of your e-bike. This system is ideal for child and cargo trailers, since it offers a particularly stable connection.

The axle coupling impresses with its fast mounting and its versatility for different trailer types. Particularly with frame locks and special coupling systems it is securely and easily attached in just a few steps.

Tip: Make sure the coupling system sits firmly and does not obstruct moving parts like brakes or spokes.

Image Qeridoo bicycle coupling

Seatpost coupler: practical with pull handles

This coupler attaches below the saddle and is particularly suitable for bicycle trailers fitted with a push or pull handle. Ideal for lighter trailers or short distances.

Important: Do not max out the payload, since the weight acts higher up on the bicycle frame and can increase the risk of tipping.

Frame coupling: attach bicycle trailer to the frame

Frame couplings are a popular choice when your e-bike already has drill holes or attachment points on the frame. They are often mounted on the chainstay.

Attach Qeridoo bicycle trailer to the frame
If your bike has attachment points on the frame, you can also mount the trailer there.
This coupling system is perfect for stable connections and particularly useful for e-bikes with fixed mounting points. Important: Make sure the coupling system ensures frame protection, especially with sensitive materials like aluminum or carbon.

Extended rear axle: when space gets tight

Some e-bikes with large batteries or special frame designs require an extended axle to securely attach the coupling. This is because the distance between the axle and the frame must be enlarged to create space for the coupling.

Here you can use adapters or special axle systems, that enlarge the required distance and enable a secure connection . Make sure the extended axle is compatible with your e-bike model, to ensure stability and safety during the ride.

This option is particularly recommended if you want to safely and reliably attach cargo trailers or heavily loaded child bicycle trailers to the e-bike .
Hitching up the bicycle trailer

Hitching the bicycle trailer to the coupler

Once the axle type has been determined and the matching coupler correctly fitted to the e-bike, the last step follows: hitching the bicycle trailer securely. A careful connection ensures not only stability but also maximum safety while riding.



Here is a step-by-step guide to attaching the bicycle trailer:

1. Insert the tow bar into the coupler:
Carefully insert the trailer's tow bar into the coupler. Make sure it is seated correctly to ensure a secure connection between trailer and bicycle.

2. Fit the safety pin:
Once the tow bar is in the coupler, fit the safety pin to secure the tow bar. The pin prevents the tow bar from coming loose unintentionally while riding.

3. Attach the safety strap to the bicycle frame:
Attach the safety strap to the bicycle frame for additional safety. Make sure the strap is neither too loose nor too tight. Too much tension could hinder steering movements, while a strap that is too loose reduces stability.

4. Avoid contact with moving parts:
Make sure that the safety strap and the tow bar do not touch any moving parts such as the disc brake. This could cause problems with braking performance or steering.

With these simple steps you can make sure your bicycle trailer is properly attached and that you can enjoy a safe ride.

Tip: A coupler anti-rotation device ensures that the coupler does not twist or come loose unintentionally while riding. It guarantees a stable and secure attachment of the trailer to the e-bike, even on demanding bends, at higher speeds or on uneven terrain.


Last updated: August 6, 2026

Legal requirements

What legal requirements apply to bicycle trailers on an e-bike?

Besides fitting everything correctly, you should also know the legal framework before heading out with a trailer on your e-bike:

  • Maximum speed: With a trailer, your e-bike may provide assistance up to 25 km/h. S-pedelecs (up to 45 km/h) are not approved for trailer use.
  • Minimum age: Anyone towing a child trailer must be at least 16 years old.
  • Number of children: A maximum of two children up to the age of 7 may ride in the trailer, buckled up and with a helmet recommended.
  • Total weight: The permissible total weight of e-bike and trailer must not be exceeded – the manufacturer's specifications in the user manual are decisive here.
  • Standard & marking: The trailer should comply with DIN standard EN 15918 and carry a TÜV or GS test seal.
  • Lighting: Reflectors and working lights are mandatory so that you are clearly visible in traffic.

Important: This information is for guidance only and does not replace legal advice – when in doubt it is worth checking the StVZO or asking your specialist dealer. 

Safety features

What safety features should a good bicycle trailer coupler have?

To keep your child safe, the coupler should not only be securely fitted but also come with the right safety features:

  • TÜV or GS certificate: A test seal confirms verified safety and material quality.
  • Coupler anti-rotation device: Prevents the coupler from twisting or coming loose unintentionally while riding – especially important on bends or uneven terrain.
  • Safety pin: Secures the tow bar in the coupler and prevents it from coming loose unintentionally.
  • Tether or safety strap: Serves as additional protection should the main connection fail, and should be attached to the frame on every ride.
  • Lockable coupler (optional): Offers additional theft protection when the trailer is parked while you are out. 


"You can tell a good coupler not just by the brand but by the details – an anti-rotation device, a safety pin and an additional tether are therefore standard on our systems, not optional."

— Wilhelm Wenzel, Head of Development at Qeridoo 

Autor Wilhelm Wenzel

What should you look for when buying a universal coupler?

Universal couplers – often also called quick-release couplers – are compatible with many types of bicycle and a popular choice if you want to stay flexible. When buying, look out for the following:

  • Compatibility with your axle type: Universal couplers usually fit quick-release axles, but often need an additional adapter for thru-axles.
  • Adjustability: Make sure the coupler can be adjusted to different axle lengths and diameters.
  • Material quality: High-quality universal couplers are made of sturdy, corrosion-resistant material.
  • Certification: Even with universal solutions it is worth looking for a TÜV or GS seal.
  • Manufacturer approval for e-bikes: Not every universal coupler is explicitly approved for e-bikes – check this in advance, especially with a higher total weight. 

FAQ – Die häufigsten Fragen zu Fahrradanhänger Kupplung und E-Bike

Welche Kupplung brauche ich, um einen Fahrradanhänger am E-Bike zu befestigen?

Das hängt vom Achsentyp des E-Bikes ab. Für Schnellspanner-Achsen (Quick-Release) gibt es spezifische Achskupplungen, die in wenigen Schritten montiert werden können. Für moderne E-Bikes mit Steckachsen wird häufig ein Adapter benötigt, der mit einem Drehmomentschlüssel befestigt wird. Bei älteren Modellen mit Vollachsen sind Polygonadapter oder spezielle Achsenadapter die richtige Wahl.

Zuerst den Spannhebel öffnen, um die Achse freizugeben. Dann den Kupplungsadapter auf die Achse schieben und an der gewünschten Position platzieren. Die Schraubbolzen handfest anziehen und den Spannhebel schließen, bis er stramm sitzt – nicht mit Gewalt schließen. Ist das Gewinde zu kurz, kann eine längere Schnellspannachse als Ersatz montiert werden.

Die Steckachse erfordert in den meisten Fällen einen kompatiblen Adapter – zum Beispiel den Qeridoo Steckachsadapter – sowie einen Drehmomentschlüssel für die korrekte Anzugskraft. Wichtig ist, dass der Adapter mit dem E-Bike-Modell kompatibel ist und die Kupplung nach der Montage korrekt ausgerichtet ist, um eine sichere und reibungslose Fahrt zu gewährleisten.

Ja, die Kupplung Fahrradanbindung für Fahrradständer kann an Rahmen mit einem KSA 18 Standard (18 mm Lochabstand) befestigt werden. Alternativ kann der Polygonadapter Giant M10 x 1,5 (KUFA-System) oder Giant-Adapter M10 x 1,5 (becco-System) an einer Anhängeraufnahme an Fahrrädern der Marken Giant, Liv und Momentum angebracht werden.

Diese Kupplungsarten bieten eine stabile Verbindung und sind besonders bei E-Bikes mit festen Montagepunkten geeignet. Bei empfindlichen Rahmenmaterialien wie Aluminium oder Carbon muss unbedingt auf Rahmenschonung geachtet werden.

Eine Kupplungsverdrehsicherung verhindert, dass sich die Kupplung während der Fahrt ungewollt verdreht oder löst – besonders bei Kurvenfahrten, höherem Tempo oder auf unebenem Terrain ein wichtiges Sicherheitselement. Sie empfiehlt sich für alle, die regelmäßig mit dem Fahrradanhänger unterwegs sind und maximale Verbindungssicherheit wünschen.

Zunächst sollte die Herstellerfreigabe des E-Bikes für den Anhängerbetrieb geprüft werden – nicht alle Räder sind dafür ausgelegt. Carbonrahmen können unter der zusätzlichen Belastung brechen und sind in der Regel nicht für Anhänger geeignet. Der Anhänger muss zudem der DIN-Norm EN 15918 entsprechen und die Gewichtsgrenzen des E-Bikes – sowohl Anhängelast als auch zulässige Gesamtbelastung – dürfen nicht überschritten werden.

Nach der Montage alle Schrauben und Befestigungspunkte auf festen Sitz überprüfen, sicherstellen, dass sich keine beweglichen Teile berühren und eine kurze Testfahrt auf ruhigem Gelände durchführen. Dabei auf ungewöhnliche Geräusche, Wackeln oder Einschränkungen der Lenkung achten. Vor jeder Ausfahrt sollte die Kupplung kurz auf Festigkeit und falls vorhanden der Sicherungssplint auf korrekten Sitz überprüft werden.

Eine Universalkupplung, oft auch Schnellspann-Kupplung genannt, ist mit vielen Fahrradtypen kompatibel. Beim Kauf solltest Du auf die Kompatibilität mit Deinem Achsentyp, ein TÜV- oder GS-Siegel sowie die ausdrückliche Freigabe für E-Bikes achten. 

Mit Anhänger darf Dein E-Bike maximal 25 km/h fahren, die fahrende Person muss mindestens 16 Jahre alt sein, und der Anhänger sollte der DIN-Norm EN 15918 entsprechen. Zusätzlich gelten Gewichtsgrenzen sowie eine Pflicht zu Beleuchtung und Reflektoren.