Unfortunately, the legislation regarding bicycle trailers is confusing, and as a result, many different opinions and interpretations circulate online. On this page, we will address all the important aspects and attempt to provide clarity. We also offer recommendations for interpreting the current legislation (without being legally binding).

General mention in StVZO § 63a Bicycles and bicycle trailers

A somewhat new paragraph specifically deals with bicycles and bicycle trailers. It primarily replaces the Vienna Convention on Road Traffic of November 9, 1968, and establishes a clear definition in German law. Regarding bicycle trailers, Section 63a, "Bicycles and Bicycle Trailers," states the following:

(3) Bicycles and bicycle trailers may only be used on public roads if they comply with the provisions of this Ordinance, the official notices published for its implementation and the state of the art at the time of manufacture.

Dimensions according to § 32 StVZO

In connection with the definition of bicycles as non-motor vehicles (read more), there is considerable discretion regarding bicycle trailers, which is constantly hotly debated. At its core, the problem lies in the lack of classification. Are bicycles most similar to motorcycles, and should the aforementioned dimensions and regulations therefore be applied? Or should the generally established values for the "other" class be used?

We don't want to delve too deeply into the matter here, as even after consulting with the German Cyclists' Association (ADFC), we couldn't provide a 100% definitive answer regarding the dimensions. The biggest and most important issue when towing a trailer is defining the permitted width. The wider the trailer, the less likely it is to make sensible use of the cycling infrastructure. Our recommendation, based on Section 32 of the German Road Traffic Licensing Regulations (StVZO), paragraph (9), is therefore:

Trailer behind a single-track cargo bike or bicycle: <1.0m

Trailer behind a multi-track cargo bike or bicycle: <2.0m

This recommendation is based on the maximum dimensions for bicycles and 25 km/h pedelecs (bicycles with auxiliary motors) in general. This means you won't have to explain yourself in the event of a stop.

In principle, a bicycle trailer could be 18.75m long and 4.0m high. Here, too, we recommend using the dimensions of motorcycles and limiting the length to 12.00m and the height to 2.5m. Either way, these are monstrous dimensions for transporting things by bicycle.

Since no specific definition for bicycles is provided here, these are assumptions based on the weak legislation. In general, all models on the market are significantly smaller, and all trailers we offer from Carla Cargo and beyond meet this narrower recommendation.

Can I simply attach a bike trailer to my e-bike?

As mentioned several times, the law considers bicycles and pedelecs with a rated power of 250W and assistance up to 25km/h to be equivalent. This means that no specific approval is required for the use of bicycle trailers behind a pedelec. The situation is different for the significantly faster S-pedelecs, which require insurance, tax, and license plate registration. These are considered motor vehicles, and to date, we are not aware of any bicycle trailer approved for use behind an S-pedelec.

The basic rule is: The bicycle manufacturer, regardless of whether it is an (E)-cargo bike or (E)-bike, must have approved trailer operation.

Some bicycles are excluded from trailer operation by the manufacturer, e.g. the premium cargo bike CaGo.

How heavy can a bicycle trailer be?

As with almost all aspects of bicycle trailers, opinions differ widely regarding weight and the "necessary" braking system. A 1999 leaflet is often cited that limits unbraked trailers to 40 kg and braked trailers to 80 kg. This leaflet was issued as a "guideline on the state of the art" for trailer manufacturers. The associated type approval failed in the Federal Council, and thus this leaflet has no legal relevance.

As with dimensions, the legal framework is still unclear in many details. Therefore, we follow the recommendations of our manufacturer. Unbraked trailers should not weigh more than 100 kg to avoid overloading the braking system of the towing bicycle. In this case, the performance of the braking system must be assessed on a case-by-case basis. We recommend a bicycle with disc brakes, as these provide solid braking performance regardless of the weather (wet conditions).

For trailers weighing more than 100 kg, we recommend an overrun brake. This significantly reduces the load on the towing bike's braking system, thus significantly increasing road safety.

Lighting system according to §67a StVZO

The legislation regarding lighting systems has been very well formulated in Section 67a of the German Road Traffic Licensing Regulations (StVZO) as of June 1, 2017. Reflectors and position lights are specified depending on the width and length of the trailer. The most important point, in our view, is the requirement for a rear light on the left side of all trailer types if 50% of the illuminated area of the tail light is obscured (which is almost always the case). This must always be observed during operation. All other points, especially regarding reflectors, are generally followed by German and European manufacturers and therefore pose no objections.