What is a caravan chassis?

In this blog post, we will answer the following question: What is a caravan chassis? We will also review one of the most popular chassis for RVs: AL-KO. 

What is a caravan chassis?

A caravan chassis is the structure on which the caravan is built. This is also the part on which the caravan towing hitch is mounted. The chassis designates the structure to which all the elements making up a caravan are fixed. Made of composite materials or metal in the design of current land vehicles, it is perfectly rigid to fully play its role of backbone.

The chassis and the body of the caravan

If we compare it to the body, we can define the chassis of the caravan as all the structures contributing to the running function with the exception of the accessories, transmissions and the engine. Hence its importance in the operation of caravans regardless of the model or brand.

A caravan chassis comes in a variety of forms. We have indeed different types of chassis offered by its designers. We thus have:

  • The H-frame or ladder chassis is still used in the manufacture of some 4X4s and trucks
  • The separate chassis placed in the basement resting on a central beam of large caliber RVs
  • The tubular chassis/self-supporting frame – a version exclusively reserved for certain caravans. This is characterized by great rigidity and is particularly lightweight.

How much weight can a caravan chassis support?

How much weight a caravan chassis can take will depend on whether you are going for a single axle or tandem axles. Generally speaking, single axles are limited to 20,000 pounds, and axles spaced more than 40 inches and not more than 96 inches apart (tandem axles) are limited to 34,000 pounds. Gross vehicle weight is limited to 80,000 pounds. 

By studying the maximum weight that the chassis of the vehicle can support, the weight of the vehicle in question and what is the mass by which the engine of the vehicle can be supported, the car manufacturer determines the maximum towable weight of their vehicle.

How do I know which chassis my caravan has?

It’s no wonder if you don’t know which chassis your caravan has. The type of chassis is often not mentioned in the factory information. In principle, half caravans have a BPW frame and the other half caravans have an Al-ko frame. The type is often difficult to recognize. For this, you can contact the experts in the technical department. 

With the help of a photo with a description, they can see what type of chassis is under your caravan and which caravan mover is best suited. There is one type of frame that can be recognized, the M frame from Al-KO imprinted in the chassis beam.

Is AL-KO indeed the best caravan chassis?

If we are to believe the glossy brochures and dealerships, the AL-KO chassis would be the panacea for those who want a safe, comfortable and practical motorhome. Everyone, in short. 

 First of all, you have to know what is behind the name “AL-KO chassis” for caravans. This is a chassis developed by the company AL-KO. Designed to be associated, by bolting, to the carrier’s cabin, it replaces the original platform. 

Constructed of very strong, hot-dip galvanized steel, it comes in the form of an assembly of C-sections: two main longitudinal side members associated with cross members, like the ladder frames of heavy goods vehicles. Regarding the axle (there can be up to three), it has independent wheels, the suspension being provided by torsion bars coupled to shock absorbers.

What are the advantages of the AL-KO chassis?

  1. The weight: The construction of the AL-KO chassis is special. Although the steel used is strong and therefore relatively heavy, the set is advertised as being a hundred kilograms lighter than the original one. Thanks to punctures made at regular intervals, the total mass remains contained, which helps to promote the payload. A good point on the largest motorhomes, therefore the heaviest.
  1. Lowering the centre of gravity: Most AL-KO frames are low (-14 or -20 cm), but above all, due to their ladder structure, it is possible to install certain equipment (tanks, heating). Likewise, AL-KO is able to provide tailor-made products to motorhome manufacturers (length, width, positioning of cross members, size and height of the hold, etc.), allowing them to optimize the layout of the various technical elements. 

To the benefit of the centre of gravity, therefore, but also of the distribution of masses between the front and rear axles, as well as in relation to the sides of the vehicle. With a notable influence on handling.

  1. A widened rear track: On AL-KO chassis, the rear track, the distance between the two wheels, is greater than on the original manufacturers’ chassis: up to 2,100 cm (compared to the original 1,810 for Fiat Ducato, Citroën Jumper and Peugeot Boxer). A guarantee of stability is beneficial to road holding, but also welcome in case of side wind or when overtaking (or overtaking) by a heavyweight.
  1. The possibility of a double floor: Of course, if you think of a double floor, you can immediately imagine a lot of storage space that is both accessible from the outside and through hatches in the floor. The interest is obvious here, but there is a second advantage to the double floor: insulation. Indeed, this air gap wedged between two walls slows down heat exchange, making it easier to keep the cell hot or cool. What to save some money.

What are the drawbacks of the AL-KO chassis?

  1. The price: Opting for an AL-KO chassis means, at the very least, offloading an additional $ 5,000. A tidy sum which, in itself, gives food for thought and weighs the pros and cons.
  1. Close to the road, even a little too much: For the lowered versions (22 cm), the ground clearance can become problematic in certain conditions: speed bump a little too pronounced, height difference accentuated … Not to mention that, sometimes, certain mechanical elements, such as the escapement, or technique, such as the drain system, can be placed even lower. So be careful.

Is the AL-KO chassis better for a caravan?

Clearly, if the price is not an issue for you and the benefits we have listed seem decisive to you, don’t hesitate. Be aware, however, that while you can’t afford it, you won’t have to settle for a more standard motorhome. If the practicality of a double floor is obvious, we can live very well without it, and the handling of vehicles on the original chassis is not a problem (the rear track of the chassis ” special camping- because ” Fiat Ducato is 1.89 m) and it’s a safe bet that many do not really feel the difference in this chapter.

The bottom line

A caravan chassis is an important part of the structure of the whole vehicle. We suggest you pay special attention to the recommendations of the manufacturer on how much weight your caravan chassis can support and what are the necessary maintenance for it. 

If you have any questions or comments on the content, please let us know!

FAQ on What is a caravan chassis?

How much weight can a caravan chassis take?

How much weight a caravan chassis can take will depend on whether you are going for a single axle or tandem axles. Generally speaking, single axles are limited to 20,000 pounds, and axles spaced more than 40 inches and not more than 96 inches apart (tandem axles) are limited to 34,000 pounds.

What to pay attention to when buying a chassis? 

Before buying a caravan mover, there are other points that you should pay attention to regarding the chassis:

  • Shock absorbers: It is possible to mount a caravan mover if you use shock absorbers, but be careful that they do not touch each other when you install the caravan mover.
  • Spare wheel carrier: If you have fitted a spare wheel carrier to your chassis, the question is whether the caravan mover can be placed in front of the axle. If this is not possible, the spare wheel carrier is moved or removed.

How much weight can you put in a caravan?

The weight that you can put in the caravan should be either 10% of the ATM (Aggregate Trailer Mass) or a maximum of 350 kg ( 770 pounds). The manufacturer should usually specify the maximum permissible ball weight, which should be between 8-12% of the weight of the caravan.

What is the maximum weight for a single axle caravan?

The maximum weight for a single axle caravan is limited to 20,000 pounds, and axles spaced more than 40 inches and not more than 96 inches apart (tandem axles) are limited to 34,000 pounds. Gross vehicle weight is limited to 80,000 pounds. 

How is payload calculated on a caravan?

To calculate the payload on a caravan, subtract the Tare weight (the unladen weight of the van, as it left the factory, minus any dealer-added features) from the van’s Aggregate Trailer Mass.


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