FAQ

A subframe is a vital component of any expedition vehicle, it is the metal frame that supports the habitation box and holds it to the truck chassis.

If you are mounting a habitation box onto a truck then yes, you need a subframe that allows relative movement between the chassis and frame. The options are either a rail on rail subframe or a 4-point torsion free subframe. Both of these reduce the forces on the box, which is needed as a box is more delicate than the steel bodies the trucks are originally designed for. The movement also allows for the truck to have greater articulation and superior offroad ability. We would never recommend hard mounting a subframe directly on a chassis.

A torsion free, or 4-point subframe is mounted on 4 pivoting rubber mountings, two on an axis across the frame of the truck and two on an axis along the length of the truck. This allows the truck’s chassis to twist without imparting any of the forces into the subframe and therefore the habitation box.  On a truck it is often necessary to combine this with an intermediate frame to protect the chassis. Due to its complexity and the additional material and labour required in its construction the 4-point torsion free subframe is the most expensive of the two options.

A rail on rail subframe sits directly atop the chassis rails and is held down with a mixture of fixed and flexible mountings. The flexible mountings are positioned at the extremities of the frame and allow some relative movement of the chassis without twisting the subframe, but in cases of extreme articulation this will still occur when the flexibility of the mounting is exceeded. A rail on rail subframe is a more cost effective solution and can sometimes reduce the weight or overall height of the vehicle compared to a 4 point torsion free subframe.

An intermediate frame sits atop the chassis rails and acts as a mounting point for a 4-point torsion free subframe. Its purpose is to protect the chassis from overtwisting during extreme articulation and distribute the point loads from the subframe. Most trucks require these frames to prevent damage to the chassis.

If you want the ultimate offroad option, get a 4-point torsion free subframe. This will allow the vehicle to unleash its full potential offroad without worrying about damaging the box or the vehicle. The rubber mountings also help to absorb vibrations, so it is a good choice if you are looking to do extended periods of non-metalled roads at cruising speed, especially washboard roads found in dry climates.

If you are not planning on doing extreme offroad and pushing the capabilities of the truck, then a rail on rail subframe is likely the best option.

All our panels utilise a 2mm woven GRP skin inside and out with a highly insulative XPS foam core.

The woven GRP is significantly stronger and has much higher impact resistance than standard GRP, which makes it ideal for an expedition vehicle where it is likely to get a few knocks.

The XPS foam core is done in two layers, with staggered joints so that there are no potential weaknesses or cold spots in the panels.

Our wall panels are 64mm and our floor is 84mm. The walls have an R-value of approx. 2.4m².K/W and the floor 3.2m².K/W. 

All our subframes are designed specifically for each vehicle on SolidWorks CAD, this allows us to optimise them for performance and weight.

Our subframes are generally made from S355 high strength steel and are hot dip galvanised for corrosion protection and longevity.

On some vehicles we can also offer a fully stainless steel subframe for the ultimate longevity and it’s amazing looks.

This crucial bond needs to be high strength to cope with the rigours of offroad driving but also not impede the thermal performance of the habitation box. Our solution is to use GRP bolts combined with low profile stainless steel spreader plates.

The GRP bolts have a thermal conductivity over 100 times lower than their steel equivalent and are impressively strong. 

We’ve been in business over 40 years and have a wealth of experience with Unimogs & 4x4 trucks, engineering expertise and a healthy dose of common sense.

 Our camper boxes and subframes are designed used the latest Solidworks CAD software. You can find more details on our Technical Information page.

 We have a dedicated and experienced team on the end of the phone or email to offer support throughout the build and your ownership of the vehicle.

We provide a 2 year warranty on our camper boxes and subframes. Please contact us for more information.

We can arrange shipping for subframes and camper boxes worldwide.

We specialise in 4x4 vehicles 7500kg gross vehicle weight and larger so we don’t get involved with builds on smaller vehicles.

As a rule the answer is “No” because we cannot guarantee the quality of construction of the subframe. However in some cases especially if the subframe is made by a reputable manufacturer we will consider this.

Yes! We’re very used to offering support by phone, WhatsApp and email to our customers all over the world.

No. We do not supply panels for self-assembly.

We specialise in supplying an empty camper box with windows and doors mounted to a subframe and fitted to your vehicle.

We work with partners in the UK who can complete interior and electrical work.

Certainly! We work closely with our customers on the design of their box, subframe and accessories to ensure that they tick all the boxes.

 Do keep in mind that constant design changes will take time and therefore result in extra cost.

Our payment structure is typically:

• 10% deposit to reserve your build slot
• 65% deposit 8 weeks prior to build slot
• Balance due upon completion

However we’re happy to work with our customers to find a schedule which works for both parties.