Retrofitting Full-Extension Drawer Runners: Matching Runners for Kika Desks

March 23, 2026

A full-extension runner allows the drawer to be pulled out 100% from the cabinet carcass, whereas a partial-extension runner stops at around 75%.

Anyone using a standard commercial desk, for example from Kika, intensively often reaches the limits of the factory-fitted hardware. Many standard furniture items are delivered from the factory with basic roller runners as partial extensions. This leaves the rear section of the drawer difficult to access. A desk without full extension is like a toolbox whose rear compartments are permanently blocked. Retrofitting telescopic ball-bearing runners is a standard technical task that can be carried out precisely with accurate measuring and attention to fundamental installation dimensions.

This guide explains the technical parameters that must be observed when selecting the correct runners for desk drawers.

Key Purchasing Criteria for Retrofitting

Before dismantling the old runners, the exact dimensions of the carcass and the drawer must be determined. The compatibility of new fittings depends on three critical factors.

1. Installation Width and Side Clearance

The decisive dimension when changing from one runner to another is the installation gap between the outer drawer side and the inner carcass wall. Standard telescopic runners require an exact side clearance of 12.7 mm per side. If the gap is smaller, the runner will jam. If it is larger, the ball bearings will not engage correctly in the profile, which can cause the runner to tear out. If dimensions differ, spacer strips made of wood or plastic must be fitted underneath.

2. Nominal Length of the Runner

The nominal length describes the length of the closed runner. It is based on the depth of the drawer. The runner must never be longer than the clear internal carcass depth of the desk. For compact desks (for example 90 cm wide with shallow depth), drawer runners 300 mm or drawer runners 350 mm are often used. On standard office desks with a depth of 70 cm, drawer runners 500 mm or drawer runners 550 mm are the standard size. Measure the outer edge of the drawer side from the back panel to the inside edge of the front.

3. Load Capacity in Kilograms

Desk drawers for pens and paper manage easily with a standard load capacity of 30 kg to 45 kg. However, if heavy lever arch files, tools, or IT hardware are to be stored in the desk cabinet, upgrading to heavy duty drawer runners is required. These profiles are manufactured from thicker sheet steel and accommodate loads of 80 kg and more.

Overview of Types and Mechanisms

The furniture fittings market offers various construction types. When retrofitting existing desks, distinguishing between runner types is essential.

Runner Types

Ball-bearing runner: This is the standard choice for retrofitting full-extension drawer runners. It is screwed to the side of the drawer and consists of interlocking steel profiles and small steel balls. It is forgiving of minor tolerances and easy to install.
Roller runner: A simple design with plastic rollers. It is usually screwed under the drawer base along the edge. Anyone wishing to replace existing roller drawer runners generally switches directly to ball-bearing runners for ergonomic reasons.
Undermount runner: These runners are mounted invisibly beneath the drawer base. Undermount drawer runners offer the smoothest movement. However, retrofitting is complex because the drawer requires precise routing on the back panel and an elevated base. For standard retrofits on Kika desks, they are usually unsuitable unless the drawer box is completely rebuilt.

Additional Features: Soft-Close and Opening Mechanisms

A clear choice must be made regarding the mechanism. The two most popular functions are generally mutually exclusive from a technical standpoint.

Soft-Close: An integrated hydraulic damper catches the drawer over the final few centimetres and pulls it shut smoothly and silently. Soft-close drawer runners require a traditional furniture handle on the front to overcome the spring resistance upon opening. A simpler variant without a damper, but with a closing spring, is self-closing drawer runners.
Push-to-Open: This mechanism operates with a tensioned spring. Light pressure on the handleless front releases the catch, and the drawer pops open by a few centimetres. Push-to-open drawer runners are mandatory if the desk is to have a minimalist design without protruding handles.

Important: Soft-close actively pulls the drawer shut, whereas push-to-open actively pushes it open. Combining both systems within a single standard fitting is mechanically contradictory and not intended.

Which Runner for Which Desk?

Choosing the right hardware depends on the construction of the desk.

For small desks (e.g. in hallways or children's bedrooms): Space is limited here. Measure the exact depth. Often, only drawer runners 400 mm or drawer runners 450 mm will fit. A standard full-extension runner without soft-close is usually sufficient.
For deep desks (120x70 cm) and pedestals: Maximum storage space is required here. Utilise the full depth with drawer runners 600 mm. If heavy catalogues are being stored, ensure a load capacity of at least 45 kg.
For desks with handleless fronts: You must choose the push-to-open variant. Ensure that a gap of approximately 2.5 mm to 3 mm remains between the closed front and the carcass to provide the trigger travel distance for the push mechanism.

Practical tip: If the desk is being dismantled or turned upside down for fitting the runners anyway, this is the ideal time to use a hole saw (usually 60 mm or 80 mm) to cut a cable grommet into the desktop to optimise cable management for monitors.

Installation Advice for Retrofitting

Installing side-mounted telescopic runners requires precision. A discrepancy of just a few millimetres will cause the drawer to jam or sit crookedly.

Required tools:

Cordless screwdriver
Bit PZ2 (Pozidriv)
Folding rule (tape measure) and set square
Bradawl or centre punch

Installation steps:

Separate the runner: Pull the full-extension runner out completely. Operate the release lever (usually black) on the inner rail to separate the narrow inner profile entirely from the wide outer profile.
Mount the outer profile to the carcass: Use the System 32 hole pattern (the pre-drilled line of holes in the furniture) if present. Secure the runner using dedicated Euro screws (5 mm diameter). If no pre-drilled holes exist, draw an accurately level line using a set square and pencil. Secure the profile using chipboard screws (3.5 x 16 mm). Ensure the runner sits flush with the front edge of the carcass (minus the front panel thickness if inset).
Mount the inner profile to the drawer: Mark the centre line along the side of the drawer. Screw the narrow profile on centrally. The screw heads must be countersunk completely flush into the metal, otherwise they will rub against the guide rail when sliding in.
Reassemble: Insert the drawer box with the mounted inner profiles horizontally into the ball-bearing outer profiles on the carcass. Push the drawer in with gentle, even pressure until it stops. The locking mechanism will audibly click into place.

Frequently Asked Questions (FAQ)

Can I easily replace a roller runner with a ball-bearing runner? Yes, in most cases this is possible. The requirement is that the clearance between the outer drawer side and the inner carcass wall is exactly 12.7 mm. If the gap was larger with the old roller runner, you must bridge the space using suitable washers or timber packing strips.

How do I correctly measure the required drawer runner length? Always measure the external length of the drawer box (excluding the mounted drawer front). If the drawer depth is, for instance, 450 mm, select a runner with a nominal length of 450 mm. The runner must never be longer than the clear internal depth of the cabinet carcass.

Can soft-close and push-to-open be combined? No. In standard fittings, these are opposing mechanical principles. Soft-close dampens the drawer and pulls it closed, requiring a handle to open it. Push-to-open ejects the drawer using spring tension.

What does System 32 mean for desks? System 32 is the international standard in furniture manufacturing. It describes the spacing between pre-drilled holes in the carcass side. The distance from hole centre to hole centre is exactly 32 mm, and the drill hole diameter is usually 5 mm. Modern telescopic runners feature hole patterns designed to align precisely with this grid.

How much load capacity does a desk drawer need? For normal day-to-day office use (pens, hole punch, paper), a standard load capacity of 30 kg is completely sufficient. However, if heavy tools, rechargeable batteries, or suspension files with paper documents are stored in the drawer, choose a runner rated for at least 45 kg or a heavy-duty runner.