Motorhome Accessories

Expertise and purchase advice

Find out everything you need to know about towbars, rear rack systems, payload and load capacities.

The D-value is an indication of the strength of a towbar. It can be calculated using the following formula:

D = G(K) x G(A) x 9.81
     G(K) + (A)

Where G(K) is the gross weight of the towing vehicle in tonnes and G(A) is the gross weight of the trailer, also in tonnes. For example, a Fiat Ducato with 3.5t gross weight and towing capacity of 2t requires a towbar with a minimum D value of:

D = 3.5 x 2.0 x 9.81 = 12.50 kN
    3.5 + 2.0

The actual permissible trailer load is based on the value stated in section 28 or 01 of the vehicle registration documents. Of all the given values it is always the lowest value that should be adhered to.


The X dimension

The X dimension specifies the overhang of the mobile home body over the series chassis. When ordering, please specify the dimensions entered on the drawing if your vehicle should not be listed in
our database. (contact us in case of doubt) If a tank, storage compartment or similar is installed in your vehicle in the area labelled with “Z”, please request a special dimension sheet by telephone.



The permitted loading of a motorbike carrier on the motorhome depends on the permitted rear axle load of the vehicle and the technically permitted loading of the carrier. Also important are the detailed weights that the trailer manufacturer individually approves for their vehicles. There are different chassis and frame extensions that can be loaded to different extents. The possible payload can be calculated with the following formula:

  • F(L) = permissible cargo mass
  • F (HA) = difference between permissible (from vehicle registration document) and real/weighted rear axle load
  • A = wheelbase
  • B = effective lever arm of the cargo mass (for an approximate calculation it can be assumed that the centre of gravity of the load is approx. 350 mm behind the end of the vehicle).

F(L) = F(HA) x A
        A + B

If you should require a larger load than calculated, it might be possible to increase the axle load with a payload increase.



Our experience and expertise enable us to offer towbars for most European vehicles. Towbars for other vehicles can be produced individually by us or by our service partners. Please observe or check the permissible trailer loads for your vehicle (vehicle documents, COC papers). Alternatively, in the absence of these documents, a solution can be found in consultation with TÜV.


Many factors must be taken into account to assess the load that can be "carried" by a motorhome. The general vehicle data such as rear axle load and total weight must be taken into account when determining the vehicle load capacity. It is also necessary to clarify the load-bearing capacity of the motorhome chassis and any chassis extension.


In many cases an original chassis (e. g. from Fiat/Mercedes/etc.) is too short to build a motorhome. A frame extension is therefore usually necessary. It carries the rear garage or the entire rear section of the vehicle.

As a rear garage with, for example, a payload of 150 kg has considerably lower forces than a 2,000 kg trailer coupling or an additional load carrier, the frame extension must be reinforced with components tested by the EC in order to create a stable connection.

The reinforcement of the frame extension with respective components is required for the assembly of a towbar or a load carrier.

Frame extension without reinforcing parts

Frame extension without reinforcing parts

Frame extension with reinforcing parts (red)

Frame extension with reinforcing parts


Simply loosen the clamping screws and locking pins on the mounting elements. You do not need any tools.

Removing the rear rack


  • A towbar and load carrier can be combined (they cannot be used at the same time)
  • Load carriers can continue to be used when changing vehicles. Only the mountings specific to the particular vehicle are required.
  • The electrical cable set must always be ordered separately (not necessary if the towbar is already present).