Most modern automatic watches wind in both directions, so a bidirectional winder suits them. A minority wind in one direction only, and those watches need the winder set to that direction or to an alternating programme that includes it. If you do not know which your watch is, set the winder to alternating, because that setting works for every movement type.
What is the difference between bidirectional and unidirectional winding?
The difference lies in the watch, not the winder. Inside an automatic movement, a weighted rotor swings as you move and drives the mainspring through a reversing mechanism. On a bidirectional movement, that mechanism captures the rotor's energy whichever way it swings. On a unidirectional movement, only one direction of swing does any winding. The other direction spins freely and contributes nothing.
A watch winder describes the same idea from the outside. A winder turning clockwise, anticlockwise, or alternating between the two is simply presenting the rotor with movement. Whether that movement is useful depends on what the movement inside can accept.
Which does my watch need?
Work through these in order:
- Check the manufacturer's documentation. Brands that publish a recommended turns-per-day figure usually publish a direction alongside it.
- Look up the calibre, not the model. Direction is a property of the movement. Two watches in the same collection can differ if they use different calibres.
- If nothing is published, use alternating. This is the safe default and it is why we build every winder in the range with it.
Alternating works universally because it includes both directions. A bidirectional movement takes energy from all of it. A unidirectional movement takes energy from the half that suits it and simply ignores the rest. Nothing is stressed by the ignored half, because a freewheeling rotor is exactly what happens on the wrist every day.
Why does my watch keep stopping on a bidirectional setting?
This is the single most useful thing to understand about direction. If your watch winds in one direction only and the winder is alternating, roughly half the rotations you have set are doing no work. A winder set to 800 turns per day is effectively supplying about 400 useful turns to that watch. If the movement needs 750, it will slowly run down even though the number on the display looks correct.
There are two fixes. Set the direction to the one the movement actually uses, or leave it alternating and raise the turns per day to compensate. Setting the correct direction is the better answer, because it achieves the result with less motor running time. Our guide to turns per day explains how to test whether a setting is working.
Can the wrong direction damage a watch?
No. Turning a unidirectional movement the wrong way does not force anything or strain anything. The rotor simply turns without engaging the winding train, which is a normal condition it experiences constantly on the wrist. The only consequence of the wrong direction is a watch that does not stay wound. That is a nuisance rather than a risk, and the broader question of whether a winder can harm a movement is covered in can a watch winder overwind or damage an automatic.
Is alternating always the best setting?
It is the safest setting, which is not quite the same thing. Alternating is right when you do not know what the movement needs, when the winder is shared between watches you swap around, or when you would rather not think about it. A specific direction is better when you know the movement and want the motor to run as little as possible for the same result.
| What you know | Setting to use |
|---|---|
| Nothing about the movement | Alternating |
| Manufacturer specifies a direction | That direction |
| Movement is bidirectional | Any setting works; alternating is fine |
| Movement is unidirectional and you know which way | That direction, at the recommended turns per day |
| Watch changes often on that rotor | Alternating |
Do all Stillwood winders offer both directions?
Yes. Every winder we sell is bidirectional and can be set to clockwise, anticlockwise or alternating. On the walnut range and the Harcourt from the two-watch up, and on the Belgrave cabinets, turns per day is adjustable separately on each rotor; the single-rotor Whitmore and Hadley and the four-rotor Marlow choose a direction from four fixed programmes instead, with no turns-per-day figure to set. On multi-rotor units such as the Kingsley and the Ravenscourt, each watch is set to what its own movement asks for, rather than everything sharing one factory default, which matters when a unidirectional watch sits next to a bidirectional one.
Does direction affect how quiet a winder is?
Indirectly. A programme that runs the motor less produces less noise across the day, so choosing the correct direction and the lowest workable turns-per-day figure is a quieter arrangement than defaulting everything to a high alternating setting. The bigger factors are the motor itself and how the case is built — the walnut and Harcourt ranges use a Mabuchi A+ grade motor with a roller bearing, chosen specifically to keep running noise low.
What about watches with a long power reserve?
Direction still matters, but the consequences are slower to appear. A movement with a long reserve can absorb several days of inefficient winding before it shows any sign of running down, which makes testing harder. Give any test a full week before you judge it, and compare the watch against a reliable clock at the end rather than glancing at it each morning.
Frequently asked questions
What does bidirectional mean on a watch winder?
It means the winder can rotate in both directions. On a Stillwood winder this is set as clockwise, anticlockwise or alternating between the two. The setting describes the winder's motion, not the watch, so a bidirectional winder can still serve a unidirectional movement.
Should I set my winder to clockwise or anticlockwise?
Use the direction your watch's manufacturer specifies. If no direction is published, use the alternating setting, which includes both and therefore suits every movement type without you needing to identify it.
Will an alternating setting wind a unidirectional watch?
Yes, but only from the half of the cycle that the movement can use. If the watch runs down on an alternating programme, either switch to the correct single direction or raise the turns-per-day figure to make up the difference.
How long does delivery take?
Orders are delivered within 5 to 8 business days.