When a watch “lives” on the wrist

A slight shudder, a secret rustling, sometimes a real buzz that passes through the case. Anyone who wears mechanical watches has already felt this intimate moment where the object seems to respond to their gesture. Where does this “vibration” in the wrist come from? Behind this sensation lie stories of free rotors, cult mechanical alarms, and even ancient singing technologies. So many chapters which say something about our sensory relationship to the measurement of time.

The most common cause: the rotor of an automatic

In the vast majority of cases, the sensation of vibration comes from the automatic winding system. At the heart of the watch, a half-metal disc – the rotor – pivots with your movements and arms the mainspring. Depending on the architecture, this rotor goes up in one direction (unidirectional) and “freewheel” in the other. When it starts to spin at full speed, released from the clutch, the case vibrates and the wearer feels this famous “wobble”.

Amateurs are well aware of the phenomenon on chronographs powered by the Valjoux 7750 (say “seventy-seven fifty” to play it for you). Its tactile signature – that short jerk when you suddenly raise your arm – has become almost an insider's rite, nicknamed the “helicopter effect”. Nothing to worry about here: it's the mechanics that are dancing.

Older still, the automatic “bumper”s of the 40s and 50s – Omega and Longines in the lead – did not have a 360° rotor, but a counterweight which abutted against springs. With each controlled impact, a little tap in the wrist: a deliciously retro sensation that collectors still seek.

• Brief, random vibration while moving: often a unidirectional rotor that freewheels.
• More marked shaking on certain chronos: typical signature of caliber families (eg: 7750).
• Slight buzzing when shaking the watch: rotor on very free ball bearings, normal if no metallic friction noise.

When the alarm goes off: Cricket and Memovox

Another source, this one voluntary: the mechanical alarm. Vulcain built its legend with the Cricket, nicknamed “The President's Watch” after having conquered the wrists of several American presidents. At the programmed time, a hammer hits a membrane or a resonant part. Result: a ringtone that vibrates frankly against the skin, with an insect timbre, nervous and charming.

At Jaeger-LeCoultre, the Memovox developed the wrist alarm clock with inimitable acoustic refinement, until the legendary Polaris of 1968 which combined alarm and diving function. These watches don't just warn you: they speak to you, physically, through a sustained micro-vibration that passes through the case and the bracelet.

• Continuous vibration for 10 to 20 seconds: typical of an activated mechanical alarm.
• “Cricket” noise or clear metallic buzzing: normal for these historical complications.
• More diffuse sensation on leather, more present on steel: the material transmits resonance differently.

What you hear...and what you won't smell

The vocabulary of watchmaking vibrations has its false friends. Tuning fork watches – like the sixties Bulova Accutron, set at 360 Hz – emit a signature soft, almost musical hum. We hear it close to the ear; you rarely feel it on the wrist. Likewise, a “high beat” caliber at 36,000 vibrations/hour crackles to the trained ear, without vibrating the skin. Conversely, smartwatches use a dedicated haptic engine: here, the vibration is purely utilitarian, designed for notification, not for mechanical poetry.

Should we be worried? Warning signs

The majority of vibrations are benign and part of the charm. But a few symptoms should alert you. A rotor should neither scrape nor “scratch”. A continuous metallic friction noise, abnormally strong vibrations with each movement, or a loss of power reserve can reveal a worn rotor axis, a tired ball bearing, or even a wandering screw in the box. Another common confusion: an ill-fitting bracelet. A hollow link or a poorly fitted end-link can mimic a vibration of movement.

• Noise of rasping or circular friction: possible rotor-bottom contact, urgent service.
• Systematic shaking with each movement and drop in performance: check the winding system.
• Repetitive dry clicking without movement of the rotor: check screws and oscillating mass.
• Nothing abnormal in the movement, but ringing on the wrist: adjust the bracelet, change end-links.

Useful reminder: magnetized movement does not cause perceptible vibration; it mainly affects accuracy. If in doubt, a watchmaker will confirm within a few minutes using the demagnetizer.

Choose the “sensation” that suits you

Like the sound of a car door, the feel of a watch is part of its identity. If you like to feel the mechanics come to life, look for:

• Unidirectional winding automatics known to be expressive (certain chronos based on 7750, numerous productions from the 90s-2000s).
• Vintage “bumpers” for a heritage tactile experience.
• Alarm watches: Vulcain Cricket, Jaeger-LeCoultre Memovox, or some more confidential Polerouter/Sub alarm watches.

If you prefer discretion:

• Opt for bidirectional windings that are generally more subdued (many modern calibers from Rolex, Omega, Grand Seiko).
• Look at the micro-rotors, often very fluid (Bulgari Octo Finissimo, some Piaget, Laurent Ferrier).
• Choose a thick leather strap which better cushions transmissions.

The extra soul

A watch that “vibrates” reminds you that time is not just digital data: it is a rhythm, an exchange. The rotor that revs up at the turn of a gesture, the alarm that hums at a café table, the slight hum of an Accutron under the sleeve... So many micro-events that signify a presence. Feeling your watch also means listening to it. And know, if necessary, how to distinguish the poetry of a well-born alarm from the signal of an expected interview. Between the two, there is everything that makes up watchmaking culture: an art of detail, movement legends, and this discreet pleasure that we carry close to us.