Gas Struts for Campervan Furniture: Selecting Newton Force for Overhead Cabinets

A gas strut opens furniture flaps using compressed nitrogen gas and holds them securely open; the required lifting force is specified in Newtons (N).

When converting a motorhome or campervan, overhead cabinets place specific technical demands on the fittings used. Whilst standard residential furniture construction primarily considers the dead weight of the flap, flap fittings in mobile applications must withstand jolts, vibrations, and temperature fluctuations. Correct specification of the gas strut is crucial to ensure the flap stays closed whilst driving, opens in a controlled manner when parked, and does not drop down when opened.

This guide is aimed at fitters and ambitious DIYers planning campervan overhead lockers or replacing existing hardware. The focus is on determining the exact holding force, installation dimensions, and professional fitting.

Key Buying Criteria for Flap Fittings in Campervans

Selecting the suitable strut is based on physical and geometric data. General guesswork inevitably leads to malfunctions: either an excessively strong strut rips the hinges from the carcass, or an underpowered strut allows the flap to sag.

Determining the Correct Force in Newtons (N)

The lifting force of a gas strut is given in Newtons. In furniture making, ratings between 50 N and 150 N are standard. As a general rule of thumb: 10 Newtons correspond to a lifting force of approximately 1 kilogram. However, because the flap is pivoted on a hinge (usually a concealed cup hinge), lever mechanics apply.

To calculate the required force, you must know the exact weight of the finished flap. Take into account the core material (for example, 15 mm thick poplar plywood, which is significantly lighter than conventional chipboard or MDF), the coating, and the weight of attached hardware. A solid furniture handle mounted on the bottom edge of the flap extends the lever arm and significantly increases the required holding force.

Example: If a flap weighs 1.5 kg including the handle, you theoretically need 15 N of holding force. Due to the unfavourable lever angle during opening, this value is multiplied in practice by a factor of 3 to 4. For a 1.5 kg flap, a strut with 50 N to 60 N is usually the correct choice.

Installation Dimensions, Length, and Stroke

In addition to force, the dimensions of the cylinder and the piston rod are decisive. The overall length is always measured in the extended state from hole centre to hole centre of the mounting brackets. A standard dimension for campervan overhead lockers frequently falls within the 245 mm - 270 mm range.

The stroke refers to the distance the piston rod retracts into the cylinder. It defines the maximum angle to which the flap can open. Ensure that the stroke suits the depth of your overhead cabinet. If the strut is too long, the flap cannot close completely; if it is too short, the flap will not open wide enough, restricting access to the locker.

Opening Angle and Door Position

The gas strut always works in conjunction with the flap hinges. Check whether the flap is mounted as a full overlay (overlay installation) or inset (inset installation). The strut must be positioned so that it does not exceed the maximum opening angle of the hinges (typically 90° to 110°), otherwise the hinges will be subjected to tensile stress every time they open, causing them to pull out over time.

Overview of Types and Options

Gas struts differ primarily in their force rating and their visual finish. Technically, they all operate on the same principle: a sealed cylinder is kept under high pressure, which pushes the piston rod outward.

• Standard Struts (50 N - 120 N): This is the regular class for typical overhead cabinets in campervans. They are suitable for flap heights of 250 mm - 400 mm.
• Heavy-Duty Struts (> 150 N): For large flaps, such as those on bench seating, drop-down beds, or extra-wide rear garage cupboards, standard versions are insufficient. Here, gas struts for heavy flaps are used to compensate for the heavy dead weight of solid components.
• Colour Variants: Because the fittings are visible when opening the cabinets, they are chosen to match the interior decor. Common options include gas struts silver for a technical appearance, gas struts black for dark decors, or gas struts white for bright living quarters.

Which Strut for Which Application? (Decision Guide)

The choice of the exact gas strut model depends on the specific installation scenario. Use the following guide values for orientation:

• If you are fitting a small, lightweight flap made of 12 mm poplar plywood (e.g. 400 mm x 250 mm), then select a strut with 50 N. Two struts (left and right) with 50 N each are often better than a single 100 N strut, as this prevents the flap from twisting during closure.
• If the flap is made of heavier material such as 16 mm melamine-faced chipboard with dimensions of around 600 mm x 300 mm, then opt for models with 80 N to 100 N.
• If you are planning a downward-opening flap (drop-down drinks cabinet), then a gas strut is the wrong product. For this application, you require dedicated flap stays that brake the downward fall and lock the flap horizontally.

Installation Advice for Motorhome Overhead Lockers

Correct installation determines the service life of the fitting. The strut acts like the muscle in a human arm – the precise fixing point relative to the joint defines the final leverage. A discrepancy of just a few millimetres in the drill hole positions dramatically alters the opening action.

Required Tools

• Cordless drill/driver
• Drill bit (Ø 2 mm for pilot holes)
• Screwdriver or bit (usually PZ2 for wood screws)
• Tape measure and square
• Suitable wood screws and furniture screws (typically 3.5 x 15 mm or 4 x 16 mm, depending on material thickness)

Installation Steps

1. Fit the Hinges: First, mount the flap to the carcass using the hinges. In campervans, concealed hinges with soft close dampers are recommended, as they pull the flap gently against the carcass over the final few centimetres and keep it under tension whilst travelling.
2. Mark the Position: Follow the manufacturer's installation template precisely. Frequently, the mounting point on the carcass is located approximately 250 mm from the front inner edge, whilst the point on the flap is measured about 90 mm from the hinge axis.
3. Screw on Mounting Plates: Secure the circular or elongated mounting plates to the carcass and flap. When working with thin poplar plywood, take care not to overtighten the screws.
4. Clip on the Strut: Most models feature a ball socket head. This is simply pushed onto the mounted bracket plates until it audibly clicks into place.
5. Observe Orientation: Install the strut so that the thick cylinder points upwards and the thin piston rod points downwards when closed. This ensures that internal oil lubricates the seal and prevents the strut from drying out.

FAQ: Frequently Asked Questions About Campervan Gas Struts

How many Newtons do I need for my cabinet flap? That depends on the weight of the flap. Weigh the finished flap (including the handle). Multiply the weight in kilograms by 10 to obtain the base force in Newtons, then multiply this value by 3 to 4 to compensate for the lever action of the hinge. A 2 kg flap therefore requires roughly 60 N to 80 N.

Can I install a stronger strut just to be on the safe side? No. An over-specified strut (e.g. 120 N for a lightweight 1 kg flap) can barely be closed by hand. The constant high resistance when closing places immense strain on the hinges and will eventually pull the screws out of the timber.

What is the difference between a gas strut and a door damper? A gas strut actively pushes a flap upwards and holds it open. A door damper (soft-close mechanism), on the other hand, is a small cylinder that merely cushions the closing speed of a door to prevent loud slamming. The two components serve entirely different functions.

Should I install one or two struts per flap? For flap widths exceeding 400 mm, two struts (left and right) should always be fitted. If you only use one strut on a single side, the flap will twist during closure and will not sit flush against the carcass. In this case, divide the calculated total force across two struts (e.g. 2x 50 N instead of 1x 100 N).

Matching Categories for Campervan Conversions

For the professional conversion of motorhomes and panel vans, you will often need other specific hardware alongside suitable flap mechanisms. To complement the struts discussed here, you will find the necessary hardware in our range for safe, long-lasting furniture construction:

• Flap fittings – An overview of all systems for upward and downward opening furniture flaps.
• Gas struts for heavy flaps – For drop-down beds and heavy components with substantial dead weight.
• Concealed cup hinges / cabinet hinges with damping (Soft Close) – The ideal pairing to support flaps securely on the carcass.
• Wood screws and furniture screws – The correct fixings for vibration-resistant grip in plywood and MDF.
• Furniture handle – Stylish handles whose weight must be factored into the Newton calculation.