If you own a Renault Master X62 motorhome—manufactured by brands such as Adria, Ahorn, Hobby, Rimor, Wanner, Etrusco, and others—and are planning to install a towbar, this guide will be especially helpful.
When fitting a tow bar on Class A, Class C or coachbuild with overcab bed motorhomes, the chassis extension becomes a key component of the entire system. Its function is to bridge the rear overhang of the living cell, ensuring both stability and safety. That’s why choosing the correct extension length is essential and must be done precisely for each vehicle model.
Common questions from motorhome owners
In forums and technical discussions, the same doubts often appear:
- What chassis extension length does my motorhome need?
- How do I measure it correctly?
- Is there a calculator that gives the exact size?
This article explains how to determine the correct chassis extension length for Renault Master III (X62) motorhomes, produced from 2010 to 2024, available with front-wheel or rear-wheel drive.
It’s also worth noting that the Renault Master shares its platform with the Opel Movano and the Nissan NV400—twin models that follow the same technical standards. As a result, the information in this article is equally useful for owners of these vehicles, ensuring they can select the right chassis extension with confidence and precision.
Why a chassis extension is necessary
On many motorhomes, the living unit extends significantly beyond the limits of the original chassis. This design maximizes interior space but creates a rear overhang that cannot be safely supported by the factory frame alone.
To address this, a chassis extension becomes indispensable. It provides the structural reinforcement needed to sustain the overhang, prevent stress on the vehicle’s frame, and guarantee safe, stable driving.
Moreover, the extension is essential when installing a tow bar, as it ensures that the towing force is distributed correctly across the reinforced structure rather than placing strain on unsupported sections. Without this component, both the safety of the vehicle and the reliability of the tow system could be compromised.
Different approaches by suppliers
- Many suppliers request photos or precise vehicle measurements.
- X-CAMPING, however, provides a digital calculator based on an extensive database, which automatically determines the correct extension length.
How the x-camping calculator works
- Uses a large database with measurements of various motorhome layouts.
- Applies correlation formulas between the total vehicle length, wheelbase, and body length.
- You simply enter the total vehicle length: you need to consult the CoC (Certificate of Conformity), which contains all the official dimensions of the vehicle; or check on the DVLA website or in the manufacturer’s technical sheet (user manual or online specifications).
Main benefit: The system provides the minimum required extension length, eliminating the need to cut or adapt standard extensions and allowing workshops to install the correct parts immediately.
Calculator limitations
Currently valid only for:
- Renault Master III X62 (2010–2024) with standard chassis and flatbed.
- Opel Movano B (2010–2021) and Nissan NV400.
- Vehicles with original chassis only (no AL-KO or special chassis).
- XIMPLIO and LEMET products (not compatible with SAWIKO, LINNEPE, SMV-Metal, Umbra Rimorchi).
Examples of compatible motorhome models
- Adria Matrix, Matrix Tour
- Ahorn Camp, Alaska, Canada, Eco
- Hobby Premium Van
- Rimor Katamarano, XGO Dynamic
- Wanner Mini
- Etrusco V-Series
Alternative manual measurement methods
For those who prefer not to use the calculator, there are still practical and reliable manual methods to determine the correct chassis extension length. These approaches require more time and attention, but they can be equally effective if carried out with care.
- Measuring the rear overhang – This involves taking the distance from the center of the rear axle to the rear wall or skirt of the motorhome.
- Measuring from the original chassis – In this case, you measure the space between the end of the factory chassis and the rear skirt.
These techniques are commonly described in technical blogs, motorhome guides, and online forums and can serve as a good starting point. Still, they lack the accuracy and reliability of a dedicated digital tool. For that reason, many professionals and motorhome owners prefer the X-CAMPING calculator, which reduces the risk of mistakes and ensures a result tailored to the specific vehicle.
Why the x-camping calculator is the best choice
The X-CAMPING calculator is designed to make life easier for anyone who needs to determine the correct chassis extension. It is a precise, intuitive, and reliable tool that takes the guesswork out of the process, offering clear results whether you are a private motorhome owner or a professional workshop installing multiple systems.
Unlike traditional manual methods, which require time, experience, and repeated measurements, the calculator delivers an instant and accurate recommendation tailored to your specific vehicle model. This not only saves effort but also helps avoid costly errors in choosing the wrong extension.
Of course, for those who prefer the classic approach—or who are working with products from other brands—manual measurements remain a valid and reliable solution. However, the advantage of the X-CAMPING calculator lies in its ability to combine speed, precision, and ease of use in a single tool.
Thanks to constant updates and continuous improvement, the calculator evolves together with new vehicle models and product lines. This ensures that it will remain a trusted, up-to-date resource for motorhome owners and professionals alike, helping them make the right choice every time.