Stabilizers
What stabilizers do, the three mounting types, how many your layout needs, and why a rattling spacebar is the most common fault on a new board.
A switch holds a keycap at one point. That is fine for a letter, and useless for a spacebar: press one end of a 119 mm key mounted on a single post in the middle and it tilts, binds, and may not register at all.
A stabilizer fixes that by giving the long key two more points of contact and linking them with a wire, so pressing either end moves the whole key down level. Every key 2u or wider needs one.
They are also the most common fault on a new keyboard, and the cheapest to fix. A rattling spacebar is more audible than anything else a board does, and twenty minutes of work removes it. The fitting and tuning is covered in fitting and tuning stabilizers; this page is what they are and which ones to buy.
The parts
Five pieces per stabilizer:
- Two housings, the plastic bodies that mount into the board.
- Two stems, the moving parts the keycap clips onto. They sit either side of the switch, under the ends of the long key.
- A wire, bent into a long flattened U, with its ends in the stems. This is what makes both stems move together.
- Screws and washers, on the screw-in type.
The switch in the middle still does the electrical work. The stabilizer does nothing but keep the key level, which is why a badly tuned one is purely a noise problem rather than a functional one.
The three mounting types
Screw-in. The housings pass through the PCB and are fastened underneath with screws. The most secure, the quietest, and the standard on custom boards. This is what you want.
Plate mount, also called clip-in. The housings clip into cutouts in the plate rather than the board. Found on prebuilts and older designs. They work, but the clips allow a little movement, and that movement is audible. Cannot be made as quiet as screw-in, and cannot be swapped for screw-in unless the PCB has the holes.
Snap-in, or PCB mount. Clips into the PCB rather than being screwed to it. Between the other two: more secure than plate mount, less than screw-in, and prone to working slightly loose over time.
If you are buying a board and have a choice, buy the one with screw-in stabilizers, or at least a PCB drilled for them.
What your layout needs
Stabilizer sizes are quoted like keycap sizes, in units. Every key 2u or wider needs one, and in practice there are only two sizes to think about: 2u for the modifiers, and one long one for the spacebar.
| Key | Keycap size | Stabilizer |
|---|---|---|
| Backspace | 2u | 2u |
| Left shift | 2.25u | 2u |
| Enter (ANSI) | 2.25u | 2u |
| Right shift | 2.75u | 2u |
| Spacebar | 6u, 6.25u or 7u | matching size |
| Numpad zero | 2u | 2u |
| Numpad plus | 2u vertical | 2u |
| Numpad enter | 2u vertical | 2u |
So:
- 60 percent, 65, 75 or TKL: four 2u plus one spacebar. Five total.
- Full-size or 1800: those five plus three more 2u on the numpad. Eight total.
- 40 percent: often just a spacebar, sometimes nothing at all.
Stabilizers are usually sold in kits sized for a layout, so a “60 percent kit” contains the right five. The one thing to check is the spacebar width, which varies between boards: standard ANSI is 6.25u, a great many custom boards are 7u. Same problem as keycaps, same lack of a workaround. Look it up before ordering.
ISO boards need a different enter stabilizer, since ISO enter is tall rather than wide.
The three noises, and what each one means
Almost all stabilizer complaints are one of these, and they have different causes.
Rattle. A loose, metallic buzz when the key returns. This is the wire moving in the stems, and it is the most common by far. Cause: not enough lubricant on the wire ends. Fix: more grease exactly there.
Tick. A single hollow click on the downstroke, often from only one end of the key. This is the stem’s underside feet hitting the PCB. Fix: clip those feet off flush, which is irreversible and what nearly everyone does.
Ping. A faint metallic ring, higher pitched than rattle. Usually the switch’s spring rather than the stabilizer, so check by pressing the stabilizer stems directly with the keycap off.
The diagnostic that saves time: press each end of the long key separately, not the middle. A stabilizer problem is almost always asymmetric, and pressing dead centre hides it.
Buying them
Two things matter and one does not.
Wire quality matters most. The wire has to be straight and evenly bent, because a wire that sits unevenly in its housings cannot be made quiet with any amount of grease. This is the variable that differs between batches of the same product, so check a new set before fitting rather than after.
Tolerance matters second. How closely the stem fits its housing decides how much play there is before you lubricate anything. Tighter is better, and it is the main thing you pay more for.
The brand matters least, within reason. Screw-in stabilizers from any of the established makers are broadly similar. Durock has been the default recommendation for years, to the point that many kits ship with them, and Everglide is the usual alternative. Both are fine. A set costs roughly 10 to 20 dollars for a full board.
What does not matter: gold-plated wires sound the same as steel ones once lubricated, and the colour of the housing is a colour.
Why this is the job to do first
If you have a new board and limited patience, tune the stabilizers and skip everything else.
Lubing the switches takes two to four hours and makes a real but subtle difference. Tuning four stabilizers and a spacebar takes twenty minutes and removes the single most obvious flaw in the way the board sounds. Nothing else in this hobby has that ratio.