Bicycle trailer

Bicycle with cargo trailer

Bicycle trailers are used to transport loads - such as children and luggage - by bicycle . The purpose of such trailers is to increase the transport capacity of bicycles further than would be possible with luggage racks , panniers and child seats . There is a wide range of bicycle trailer types that are designed for different, sometimes special purposes. In addition to industrially mass-produced bicycle trailers, there are many forms of self-made trailers, individually or in small series.

Types of bicycle trailers

Cargo trailer

Single track trailer with "Y-drawbar". On the right in the picture the rear bicycle wheel

Cargo trailers are the oldest form of bicycle trailers. In the case of cargo trailers, there are both two-lane trailers that are suitable for transporting larger loads over shorter distances (e.g. for shopping or for transporting animals) and single -lane trailers that are used for longer bike trips with a lot of luggage. These are also increasingly used by bicycle couriers . There are cargo trailers with a simple flatbed that is open on all sides as a loading area, with fixed or detachable circumferential railing to secure the load, as a box van and with textile structures in the form of bags or the like. Some of these cargo trailers are suitable for carrying loads of up to 400 kg. Nevertheless, according to the information provided by many manufacturers, the maximum permissible load is limited to 40 kg. The reason for this is the predominantly unbraked design of the trailers. The additional load has to be slowed down by the usually weakly dimensioned bicycle brakes. The respective bicycle operating instructions regarding trailer operation must be observed, because some manufacturers prohibit trailer operation for their models.

Child trailer

Child trailer with floor pan. The model shown can also be used as a stroller thanks to the handle at the rear and the fold-out front wheel under the tub. In such models, the drawbar can usually be removed or pushed in

Child trailers up to 25 kg, with universal joint coupling

Child trailers are bicycle trailers equipped with a passenger compartment. Depending on their size and design, they are suitable for transporting up to two children from a few weeks to around six years of age. Newer children's bicycle trailers are the safest means of transport for bicycles thanks to a stable passenger cell with a low center of gravity and being fitted with seat belts .

The load-bearing component of the passenger cell is a metal frame made of steel or aluminum tubing. The frame of modern models has a circumferential tube serving as a bumper on both sides, which acts as a crumple zone to protect the wheels and passengers of the trailer in the event of a collision. There are two types of passenger cells in child trailers: those with a flexible floor made of stable fabric and those with a rigid floor pan made of metal or plastic. The latter are considered the safer design. Some trailer floor pans have a spout opening for liquids to make cleaning easier and so that the tub does not fill up with water in the event of rain and a leaky roof.

The walls and roof of the passenger cell usually consist of a hood made of plastic fabric stretched over the frame with window openings to the front and on the sides, which are closed with transparent plastic or with an insect screen. Entry and exit are on the upper front. This can be closed with part of the convertible top and with a zip or Velcro to protect the occupants from the weather (sunlight, precipitation ). Stabilizing upholstery as well as lying and sitting aids and fixable carrier bags for infants and babies make such trailers interesting for parents as a mobile alternative to the car or stroller from the first months of their children's lives. In addition, thanks to the large storage space, child trailers are also suitable as load carriers, for example for shopping.

With accessories - handle bars for pushing by hand, foldable or reversible front wheels - some models can also be used as prams (see illustration). Due to their low center of gravity, stable wheels and their directional stability, some of the models equipped in this way can also be pushed while jogging and inline skating, in contrast to simpler strollers . The further equipment of child trailers depends on the manufacturer and model. It ranges from suspension, active lighting and reflectors to models that can be folded up for carrying and parking the trailer.

Swivel

Sidecar for children, 1925

In contrast to other bicycle trailers, swivels, also known as bicycle sidecars or sidecars, run on the side of the bicycle (see: → motorcycle carriage ). A swivel has only one impeller . Due to the non-rigid attachment to the bicycle, it can be rotated parallel to the bicycle along the longitudinal axis. Thus, the bicycle can be in the curve tend while the swivel and the load therein is not prone. This type of bicycle trailer is particularly suitable for long loads (for example boards and pipes), as the load can protrude beyond the trailer both forwards and backwards. Another advantage is that the cyclist can more easily observe the load, which is an advantage when transporting dogs, for example. A disadvantage of swivels compared to other types of trailers can be the greater width of the trailer combination compared to them.

Bicycle trailers for dogs

Dog bike trailers are special trailers that are designed to transport dogs. The design principle with a passenger cell consisting of a frame, floor pan and roof is often similar to that of child trailers, but they can also have a completely rigid box structure as the passenger cell. Depending on the design of the trailer, dogs up to 40 kg can be transported. Modern dog bike trailers have a stable floor pan and are usually very robust. Depending on the model, there are one or two attachment points in the passenger cell to secure the dog with a short leash while driving.

Push trailer

Requirements for the bike

The static and dynamic additional forces caused by the trailer can physically stress both the bicycle frame and the wheels to a far greater extent than using the same bicycle without a trailer. The relevant factors for this are the dead weight of the trailer and the weight of the payload as well as the driving style and the nature of the terrain. Therefore, the use of trailers is often prohibited in their operating instructions, especially for bicycles with a light carbon fiber frame .

Drawbar and coupling

Bicycle with a small cargo trailer, with a high drawbar

Bicycle trailer for heavy loads, with low drawbar

The drawbar of bicycle trailers, which in series models mostly consists of aluminum or steel tubing, connects the trailer to the bicycle by means of a trailer coupling. The drawbar is either rigidly attached to the frame of the trailer or can be folded down. Foldable drawbars can reduce the space required for the trailer and, on some models, serve as a handle so that the trailer can be used as a handcart .

Older bicycle trailer models were mostly coupled to the bicycle with a high drawbar in the area of the seat post clamping area with a ball-head trailer coupling , similar to that used in passenger cars. Today this type of coupling can only be found on two-wheeled cargo trailers. Trailers with such couplings and drawbars can also be used on mopeds . Trailer hitches attached to the seat post have the disadvantage, among other things, that when the trailer is coupled, the usability of rear wheel racks is restricted. Because high drawbars move at a low height above such luggage racks (see adjacent photo), this can usually only be used to attach panniers. One advantage of the high drawbar is that the trailer can also be used as a handcart without any modifications. Most high drawbars have their own handle at the front end for this purpose.

In the case of bicycles today, a lower drawbar with a lower strength is usually used with a coupling in the area of the rear wheel hub of the bicycle. Due to the low connection above the ground, the trailer has less tendency to rock and tilt, and the bicycle frame is completely relieved of static load. Nevertheless, the bicycle frame still has to absorb additional dynamic forces through the trailer. Low drawbars are attached to the left side of the bike. The coupling is mounted on the bicycle frame directly next to the rear hub (axle coupling) in order to reduce rolling and rocking due to the low center of gravity.

The clutch is a safety-relevant component. It must enable the angles of rotation, tilt and yaw that arise during driving and also be able to transmit the acceleration and braking forces. This is done, for example, with a strong helical spring, or alternatively a ball or universal joint as a connecting element.

Legal situation

Germany

lighting

Since June 1, 2017, § 67a StVZO has specified the lighting of bicycle trailers in detail. As with bicycles, only approved, type-approved lights may be used. The lights must be installed in such a way that they can be easily seen and are not covered. The requirements apply only to trailers from from 1 January 2018 be placed on the market .

Front:

From a width of 600 mm, a pair of white reflectors, no further than 200 mm from the outermost contour, is required.

From a width of 1000 mm, a white lamp is required on the left. Narrower trailers may also be equipped with such a lamp.
Regardless of the width, a direction indicator according to ECE R 50 (motorcycle turn signals) is permitted according to ECE R 74 as for vehicle class L1.

Rear:

A pair of large-area reflectors of category Z, no more than 200 mm from the outermost contour, is required for all trailers. An additional pair of ordinary reflectors is permitted. Triangular reflectors are not allowed.

A rear light on the left is mandatory if the rear light of the bicycle is covered by more than 50%. Another tail light on the right side is allowed.

From a width of 600 mm, a tail light on the left-hand side is mandatory.
Regardless of the width, a direction indicator according to ECE R 50 (motorcycle turn signals) is permitted according to ECE R 74 as for vehicle class L1.

Laterally:

As with a bicycle: reflective tires, reflective rims, spoke reflectors, reflective spokes or spoke sleeves.

All lighting equipment, except for direction indicators, may be combined into one device.

Dimensions, dimensions and tires

Bicycle trailers are "other road vehicles" in the sense of the StVZO. For this purpose, § 63 StVZO requires that the regulations on dimensions, axle load, total weight and tires of motor vehicles and their trailers (§§ 32, 34, 36 paragraph 1) be applied accordingly.

Dimensions (§ 32 StVZO paragraph 1–4)

General width: 2.55 m

Height: 4 m
General length: 12 m
Bike and trailer together: 18 m

The opinion is regularly expressed that the general regulations should not be applied. It is required to apply the regulations according to § 32 StVZO, paragraph 9. This is justified by the fact that bicycles, if interpreted accordingly, are not motorized motorcycles and should therefore be treated like motorcycles. It is also stated that the dimensions of 1 m wide, 4 m long and 2.5 m high would be better suited to bicycles.

This legal opinion is wrong. This can be recognized by a logical reverse conclusion: In § 67a StVZO trailers with a width of more than 1 m are expressly mentioned. If there is a lighting requirement for trailers of this width, then they must be allowed.

Dimensions and tires

Usually not relevant: The rules for motor vehicles according to §34 StVZO apply. If the trailer is lighter than 3.5 t or the towing bike is lighter than 7.5 t, none of the regulations apply. Common sense applies here: What weight can still be safely braked? What forces can the spokes and the frame absorb?

In addition, § 36 StVZO paragraph 1 applies: The tires must not damage the road surface and must be stable enough.

Other regulations

From the general part of the StVZO, Sections 30 and 30c are also applicable. The relevant sections are cited below:

§ 30 StVZO:

(1) Vehicles must be built and equipped in such a way that:

their normal traffic does not harm anyone or endanger, hinder or annoy anyone more than unavoidable,
the occupants are protected as much as possible from injuries, especially in the event of an accident, and the extent and consequences of injuries remain as low as possible.

(2) Vehicles must be built in a road-friendly manner and be maintained in this way.

(3) Vehicle parts that are important for road safety or operational safety and that are particularly easy to wear or damage must be easy to check and easy to replace.

§ 30c StVZO:

(1) No parts may protrude from the outline of the vehicles in such a way that they more than unavoidably endanger traffic.

The legislature has left a lot of room for interpretation here. If the worst comes to the worst, a court will have to decide how much risk is still unavoidable. Here everyone should think for themselves what is safely possible. DIN EN ISO 4210-2 can serve as a guideline for the brakes. There, a maximum braking distance of 7 m from 25 km / h is required for a city or trekking bike.

Passenger transport

The constitutive new version of the German Road Traffic Regulations (StVO), which came into force on April 1, 2013, also includes the closing of the previously existing loophole regarding who can be transported in bicycle trailers. According to Section 21 (3) of the StVO, people at least 16 years old are allowed to take up to two children up to the age of seven in trailers that are set up for the transport of children ; The age limit does not apply to a disabled child.

Obsolete: Leaflet on bringing trailers behind bicycles

In 1999, RWTÜV largely developed the “Leaflet for Carrying Trailers Behind Bicycles”, which the Federal Ministry of Transport issued “to give manufacturers and users of bicycle trailers orientation aids on the state of the art and handling of bicycle trailers”. It mainly relates to the safety requirements for the transport of small children. The regulation intended as a type test of the StVZO has failed in the Federal Council and is therefore of no legal relevance for cyclists. There is still no type test for bicycle trailers.

The ordinance would have restricted the length of 2.00 m, the height of 1.40 m and the total mass of 40 kg for unbraked trailers and 80 kg for braked trailers. Minimum values of the braking acceleration of the front wheel (3.4 m / s² dry and 2.2 m / s² wet) and rear wheel brakes (2.2 m / s² dry and 1.4 m / s² wet) of the towing bicycle with a total weight of 140 kg are required in it. In official German, the combination of bicycle and trailer is referred to as "train". The former should have a rearview mirror. The required minimum braking acceleration of 3 m / s² of the trailer braking system for trailers> 40 kg should be determined by determining the braking acceleration of the train, i. H. Trailer + bicycle + driver, and the braking acceleration of the sole towing bicycle are calculated back using the following formula, the latter in turn being determined from the deceleration characteristics, namely the determined braking accelerations as a function of the manual force applied.

{\ displaystyle a_ {A} = a_ {z} + m_ {f} {\ frac {a_ {z} -a_ {f}} {F_ {a}}}}

With

{\ displaystyle a_ {A} =}

Deceleration of the trailer [m / s²]

{\ displaystyle a_ {z} =}

Delay of the train (towing bike with driver and trailer) [m / s²]

{\ displaystyle a_ {f} =}

Deceleration of the towing bike with driver [m / s²]

{\ displaystyle m_ {F} =}

Bike mass (with driver) [kg]

{\ displaystyle F_ {a} =}

Trailer mass [kg]

The leaflet was controversially discussed among other things at the bicycle clubs.

Special rules for trailers behind bicycles with auxiliary engines

According to § 61a StVZO, trailers behind bicycles with auxiliary engines are only treated like trailers behind bicycles when applying the building and operating regulations (these are regulated in Sections 30 to 67 StVZO) if "the maximum speed of the pulling vehicle, determined by the design Vehicle does not exceed 25 km / h or […] the trailers were first put on the road before April 1, 1961. The regulations on trailers behind mopeds apply to other trailers behind bicycles with auxiliary engines . "

On certain pedelecs , in accordance with Section 1 of the German Road Traffic Act (StVG), the regulations on bicycles, not those on bicycles with an auxiliary motor, apply if they are "moved by muscle power and with an auxiliary electromotive drive with a rated continuous output of are equipped with a maximum of 0.25 k W , the assistance of which decreases progressively with increasing vehicle
speed and 1. when a speed of 25 km / h or earlier is reached,
2. when the driver stops while pedaling, is
interrupted ", even if they" In addition, they have an electromotive starting or pushing aid that enables the vehicle to accelerate to a speed of up to 6 km / h, even without the driver stepping on it at the same time. "Very similar defined vehicles are classified as bicycles in accordance with Section 63a (2) StVZO. Trailers behind such pedelecs are considered to be trailers behind bicycles.

Austria

Section 5 of the Bicycle Ordinance regulates how a bicycle trailer that is placed on the market or used must be designed.

In Austria , the legal requirements for bicycle trailers, both for the transport of loads and for the transport of people, are regulated in Sections 5 and 7 of the Bicycle Ordinance. The traffic law part about driving on the bicycle facilities and the general roadway is laid down in § 68 StVO . A lighting system (to have installed) during the day is still compulsory on the bicycle trailer due to the legislation, while bicycles themselves have been exempt from this since around 2000. It is unclear whether a single-track trailer angled to the side by 90 ° (such as Bob Yak ), which allows the team to stand in a stable manner, is considered to be a mandatory stand on the towing bike.

Switzerland

The following provisions apply to bicycle trailers in Switzerland:

Only one trailer may be carried on "[...] bicycles." [ Art. 68 Paragraph 1 of the Traffic Regulations Ordinance (VRV)] Exception: "For local transport, the cantonal authority, for federal vehicles the federal government, can authorize two commercial trailers." [Paragraph 2 Letter c] “Trailers on bicycles may not be more than 1.00 m wide with the load. An overhang of the load of no more than 50 cm is permitted to the rear. The operating weight must not exceed 80 kg. "[Paragraph 7]" "Operating weight" is the actual weight of the vehicle and includes the weight of the vehicle occupants, the load and, in the case of towing vehicles, the support or fifth wheel load of a coupled trailer. Art. 7 Paragraph 2 of the Ordinance on the Technical Requirements for Road Vehicles (VTS)]

"A non-triangular reflector must be firmly attached to the right and left on the front and back as far as possible. Direction indicators are only permitted if the towing vehicle is equipped with them. If the rear light of the bicycle is covered by the trailer or its load, the trailer must have a red or yellow light at the rear at night. "[ Art. 210 Paragraph 2 of the VTS]" The trailer axle must be behind the center of the loading area. "[Paragraph 3]" Trailers are to be swiveled to the towing vehicle with a reliable coupling "[Paragraph 4]" [...] Lights [... and] reflectors [... must] be kept clean. "[ Art. 57 Paragraph 2 Sentence 1 of VRV]

First: "Swivel-mounted frame structures with one or two wheels equipped with pedals, seats and a holding device", second: "Bicycles intended for children that are attached to the towing vehicle with the front wheel raised or dismantled by means of a reliable connection device", and third "Wheelchairs that are attached to the towing vehicle by means of a reliable connection device" are trailing parts and are considered trailers. [Article 210 (5) of the VTS]

The following provisions apply in Switzerland to trailer trains (vehicle combinations) consisting of bicycles and trailers attached to them:

The length of the trailer trains must not exceed 18.75 meters without a load. [ Art. 65 Paragraph 1 Letter f of the VRV] "[...] Vehicle combinations in the driving state must be able to move in a circular area with an outer diameter of 25 m and an inner diameter of 10.60 m without the projection of a vehicle part (except Rearview mirror and front direction indicator ) comes to lie on the road outside the circular area. "[ Art. 65a sentence 1 of the VRV]

Transport of cargo

The following applies to the transport of cargo on bicycle trailers in Switzerland:

"The load must be attached in such a way that it does not endanger or annoy anyone and that it cannot fall."

- Art. 30 paragraph 2 sentence 2 of the Road Traffic Act (SVG)

"In the case of [...] trailers, the load may extend no more than 5.00 m behind the center of the rear axle or the pivot point of the rear axles if it protrudes beyond the loading area."

- Article 73 paragraph 3 VRV

"A maximum overhang of the load of 50 cm to the rear is permitted."

- Article 68 paragraph 7 sentence 2 VRV &

«The load must not protrude from the side of the trailer; Exceptions apply firstly for indivisible sports equipment on sports equipment trailers and secondly for hay and straw bales and the like as well as loose hay, straw and the like on agricultural journeys. "

- Art. 73 paragraph 2 VRV

"Trailers on bicycles may not be more than 1.00 m wide with the load."

- Article 68 paragraph 7 sentence 1 VRV

"The load is to be arranged in such a way that [...] with center-axle trailers the center of gravity is in front of the axle."

- Article 73 paragraph 1 VRV

«Movable parts, such as crane arms or hooks, must be secured for travel; Lifting forks must be folded up or have clearly visible protective boxes. »

- Art. 58 paragraph 3 VRV

"Components, tools or loads that could become dangerous in the event of a collision, in particular because of points, cuts or edges, must be provided with protective devices."

- Article 58 paragraph 1 VRV

"Suitable measures must be taken to ensure that loads and parts of loads cannot easily be blown away [...]."

- Article 73 paragraph 5 1st half-sentence of the VRV

«When animals are transported, no excretions are allowed to get outside. If necessary, the floor must be provided with sufficient absorbent material. "

- Art. 74 paragraph 1 VRV

"The provisions of the Animal Disease Ordinance of June 27, 1995 and the Animal Welfare Ordinance of April 23, 2008 remain reserved ."

- Article 74 paragraph 4 VRV

"Loads, load carriers, work equipment and the like may [...] not cover the lighting fixtures."

- Article 57 paragraph 2 sentence 2 VRV

"Overhanging loads must be clearly marked day and night."

- Article 30 paragraph 2 sentence 3 of the SVG

“If loads […] are not protruding easily to the side, the outermost points must be clearly marked, during the day with pennants or boards, at night and when the weather requires it, with lights or reflectors that glow white to the front and red to the back; the reflectors may not be more than 90 cm above the ground. "

- Article 58 paragraph 2 sentence 1 VRV

"The operating weight [of the trailer] must not exceed 80 kg."

- Article 68 paragraph 7 sentence 3 VRV

"Operating weight" is the actual weight of the vehicle and includes the weight of the vehicle occupants, the load and, in the case of towing vehicles, the support or fifth wheel load of a coupled trailer.

- Article 7 (2) of the VTS

«Where there is a risk of sliding due to icing, no goods may be transported from which water drips onto the public road, e.g. B. wet gravel, sand and. like. "

- Article 73 paragraph 7 VRV

Carrying people

The following applies in Switzerland for people being carried in bicycle trailers and on trailing parts:

According to Art. 63 Paragraph 3 Letter d of the VRV, cyclists over 16 years of age may carry a maximum of two children on sheltered seats in a bicycle trailer on one and two-seater bikes. According to Article 210 Paragraph 5 Clause 1 of the VTS, trailing parts are considered to be trailers, but Article 63 Paragraph 3 Letter d of the VRV stipulates that "cyclists over 16 years of age [...] on a trailing part according to Article 210 Paragraph 5 VTS a child on one and two-seater bicycles, if he can step on the pedals or a disabled person in a wheelchair. Otherwise, "trailers for passenger transport [...] may only be used in the regional scheduled traffic of licensed transport companies." [Article 68 paragraph 4 sentence 1 of the VRV]

literature

Peter de Leuw: Choose the right bicycles, ride safely. 1st edition. Beuth Verlag, Berlin / Vienna / Zurich 2006, ISBN 3-410-16487-1 .
Michael Gressmann, Franz Beck, Rüdiger Bellersheim: specialist knowledge of bicycle technology. 1st edition. Verlag Europa-Lehrmittel, Haan-Gruiten 2006, ISBN 3-8085-2291-7 .

Web links

Commons : Bicycle trailer - collection of pictures, videos and audio files

Notes and evidence

↑ See the picture gallery