The Movement Clinic · Self-test
How to test your watch's power reserve
Applies to any mechanical watch, not only Tudor — this is one of the seven procedures in the section that isn't brand-specific.
Why this test works
The rated figure is a full-wind figure. The single most common owner error is measuring a watch that was never actually fully wound — owners who believe "you shouldn't hand-wind an automatic" start at 60% and conclude the watch is sick.
The steps
- Let the watch run down completely.
- Unscrew the crown and hand-wind clockwise slowly about 50 turns — you won't feel a hard stop, the slipping bridle just gets subtly smoother, so you cannot overwind it.
- Log T0, the moment winding stops.
- Set it dial-up on an undisturbed surface, not a desk you type at — every bump adds wind.
- Screw the crown back down and time-lapse the dial at one frame per 30 seconds to catch the exact stop moment.
- Run the whole test twice.
What to log
- Start time T0
- Number of hand-wind turns given
- Stop time
- Total hours run
- Surface and disturbance notes
Reading your result
| Pattern | What it means |
|---|---|
| Result within about 10% of spec | Normal. |
| Result 25-50% short of spec | Mainspring set, a slipping bridle from degraded barrel braking grease, dried train lubricants, or a partially seized component. |
| Manual reserve is fine but the watch dies overnight in real use | The mainspring is fine — this is a winding problem. Move to the winding-efficiency test. |
Related
Issues this test helps you get to the bottom of:
Run the symptom checker for a verdict on your exact watch.
The Movement Clinic is an independent publication by Timekeeper PH. It is not affiliated with, endorsed by, or connected to Tudor or the Rolex Group. This self-test is general guidance, not a substitute for a qualified watchmaker.