Retrofitting Larder Unit Pull-Out Runners: 70 kg to 120 kg Load Capacity for Maximum Storage

Due to its height and leverage effects, a larder unit requires specialised heavy-duty runners that can safely support the entire cabinet weight and contents of up to 120 kg as a full extension while guiding it smoothly without jerking.

Retrofitting or repairing a tall kitchen larder unit is a demanding installation task. If the existing runner jams, rubs, or can no longer support the weight of the stored items, the mechanism must be replaced with heavy-duty fittings. Standard drawer runners quickly fail here. The entire carcass of a larder unit is pulled out into the room when opened. This means that the entire dynamic load rests on the bottom runners, whilst the top guide primarily absorbs lateral tilting movements.

For joiners and experienced fitters, choosing the right new hardware comes down to exact millimetre measurements, the correct load capacity in kilograms, and the appropriate runner system. This guide provides the technical specifications for a professional retrofit.

Key Buying Criteria for Larder Unit Runners

Anyone upgrading a tall storage unit must match the hardware precisely to the carcass dimensions and the expected total load.

Load Capacity: Dynamic vs Static Load

For high-quality fittings, the stated load capacity always refers to the dynamic load – that is, the weight the runner can withstand when fully opened and during movement.

• For narrow cabinets (15 cm to 20 cm width), a load capacity of 70 kg is often sufficient.
• For wider units (30 cm to 60 cm width) and heights exceeding 1800 mm, a heavy-duty runner with a 100 kg to 120 kg load capacity is mandatory.

Tins, bottles, and flour quickly add up to a pure content weight of 80 kg. The fitting must not warp or distort under this load.

Extension Type: Why Full Extension Is Essential

A larder unit is accessed from the side. A partial extension runner, which only pulls out of the carcass by around 75%, would block access to the rearmost wire baskets or shelves. A full extension runner guarantees 100% opening. The extension length must match the internal carcass depth precisely. Common lengths for kitchen units are 500 mm or 550 mm. For extra-deep bespoke installations, runner lengths of 600 mm, 800 mm, or even 1200 mm are also used.

Installation Dimensions and Carcass Widths

The mechanism must match the internal clear width of the cabinet. Kitchen manufacturers typically work with standard external dimensions. The fittings are designed accordingly for installation in defined widths:

• For narrow recesses, a kitchen cabinet pull-out 15 cm or a kitchen cabinet pull-out 20 cm is recommended.
• Medium-sized pantry units usually use a kitchen cabinet pull-out 30 cm or 40 cm.
• For maximum storage space in wide conversion cabinets, a kitchen cabinet pull-out 50 cm or a kitchen cabinet pull-out 60 cm is installed. Here, the 120 kg rating is mandatory.

Overview of Types and Options

The runner mechanism determines the smoothness of movement and the longevity of the installation.

Ball Bearing Runners vs Roller Runners

For larder units, ball bearing runners are used almost exclusively. Hardened steel balls inside a telescopic profile made of galvanised steel ensure that no jamming occurs, even under a 120 kg load. A simple roller runner with plastic wheels would immediately give way or snap under the immense weight and leverage of the tall cabinet.

Undermount Runners for Frame Systems

Traditional larder units use a frame system. The load-bearing frame sits on a solid undermount runner, which is installed invisibly beneath the lowest shelf. At the top of the carcass, only a guide roller or a short guide rail is fitted to keep the cabinet on track. In physical terms, a larder unit behaves like a sailboat mast – the taller it is, the stronger the leverage forces acting on the lower mounting point when the unit is moved abruptly.

Soft-Close vs Push-to-Open

With high weights, damping is crucial for safety.

• A fitting with soft-close gently cushions the moving mass of 100 kg over the final centimetres and pulls the cabinet shut silently. Soft-close drawer runners prevent the force of closing from damaging the hinges or the front panel.
• Push-to-open (also known as tip-on) is an entirely different mechanism for handleless fronts. A release trigger pushes the cabinet open when the front is pressed. For heavily loaded, heavy-duty cabinets, push-to-open is mechanically demanding, as the spring force must be immense to push open 100 kg. For classic larder units, the combination of a handle and soft-close is the technically more stable solution.

Which Runner for Which Application? (Selection Guide)

• If the cabinet is narrow (15-20 cm) and ceiling-height: Choose a dedicated frame system with a bottom runner and top stabilising roller. The 70 kg load capacity is completely sufficient here.
• If the cabinet is wide (40-60 cm) and heavily loaded (crockery, tinned food): Choose heavy-duty drawer runners with at least 100 kg to 120 kg load capacity. Ensure a runner profile material thickness of at least 2.0 mm.
• If you require maximum accessibility: Choose full-extension drawer runners without exception. Measure the internal carcass depth. If the cabinet has an internal depth of 510 mm, choose a 500 mm runner.

Installation Advice for Retrofitting

Fitting a heavy-duty runner in a larder unit requires precision. A deviation of just a few millimetres can cause the front to rub.

Required Tools

• Cordless screwdriver
• Cross-line laser or long spirit level
• Tape measure and pencil
• Chipboard screws (typically 4 x 15 mm for runner mounting, 4 x 35 mm for front panel attachment)

Installation Steps

1. Dismantling: Remove the front panel and lift the old frame out of the cabinet. Completely dismantle the old runners.
2. Measuring: Determine the exact clear internal height, internal width, and internal depth. Pay attention to System 32 (32 mm hole spacing) if you wish to use existing drill holes.
3. Installing the bottom runner: Mount the new heavy-duty runner centrally on the carcass base or on the side walls (depending on the system). Use all designated fixing points to transfer the load of up to 120 kg into the timber.
4. Fitting the top guide: Fix the top guide roller or rail precisely plumb with the bottom runner.
5. Inserting the frame: Slide the supporting frame into the runners until they audibly click into place.
6. Front adjustment (3D): Hook in the front panel. Use the eccentric adjustment screws on the supporting frame to adjust the front in height, side, and tilt until the gap alignment is parallel to the adjacent kitchen units.

FAQ – Frequently Asked Questions About Retrofitting

Can I use standard drawer runners for a larder unit? No. Standard runners are usually only rated for 30 kg to 45 kg. A larder unit quickly reaches 80 kg to 120 kg. You must use heavy-duty runners, otherwise the structure will collapse downwards under the leverage force.

What length must the full-extension runner be? The runner length depends on the clear internal depth of the carcass. The runner must always be slightly shorter than the internal depth. With a standard depth of 560 mm, a 500 mm or 550 mm runner is typically installed.

How do I align a crooked larder unit front? Modern larder unit fittings feature 3D adjustment on the front brackets. Using a PZ2 screwdriver, you can adjust the panel via the adjustment screws in height (usually +/- 2 mm), laterally, and in tilt.

Why is the unit no longer closing completely? This is usually due to a faulty soft-close damper unit or a blocked ball bearing runner. If dirt has gathered in the ball tracks or the unit has been overloaded, the profile will warp. The runner must then be replaced completely.

Is base mounting or side mounting better? For classic, tall larder units, base mounting (undermount) with an upper guide is ideal, as the weight is transferred directly into the sturdy carcass bottom. For wide pull-out units beneath the worktop (e.g. 60 cm width), dual side mounting with heavy-duty runners is often preferred.

Suitable Hardware for Your Project

To carry out the retrofit professionally, our range includes the right technical components for every carcass width and load level. Browse our specialist categories to match the exact dimensions for your kitchen project:

• Complete overview of kitchen cabinet pull-out runners
• Concealed systems for the cabinet base: undermount drawer runners
• If you want to optimise the interior of your kitchen further, also take a look at practical accessories such as kitchen drawer organisers for smaller pull-outs.