Greubel Forsey Nano Foudroyante Complication
Complications

Greubel Forsey Nano Foudroyante Complication

By quattro · Oct 10, 2025 · 37 replies
quattro
WPS member · Independents forum
37 replies1861 views22 photos
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Emmanuel, known as 'quattro' on WatchProSite, initiates a compelling discussion on Greubel Forsey's Nano Foudroyante, a timepiece distinguished by its groundbreaking '10th fundamental invention.' His detailed post introduces the technical marvels of this watch, from its unique perpetual Nano Foudroyante to its significant energy efficiency. Emmanuel's personal ambivalence towards the foudroyante's visual impact, despite the watch's overall fascination, sets the stage for a rich community exchange on aesthetics versus horological innovation.

The Nano Foudroyante, which Greubel Forsey calls its "10th fundamental invention", is a 37.9 x 14.34 mm timepiece featuring:

  • A manual wind monopusher flyback chronograph.
  • A flying tourbillon — the first ever made by Greubel Forsey. 
  • A "perpetual Nano Foudroyante": a constantly-running seconde foudroyante (or lightning seconds) that subdivides each second into six parts based on the 3Hz tourbillon cage. The Nano Foudroyante is sitting on top of the tourbillon cage, that rotates once every 60 seconds while maintaining a vertical orientation.
Compared to a traditional foudroyante that consumes 30 ÎĽJ (microjoules) per jump, the Nano Foudroyante operates with only 16 nJ (nanojoules) per jump, reducing energy consumption by a factor of 1,800. Greubel Forsey calls "nanomechanics" this way of controlling energy on a nanojoule scale within a mechanical movement.

The watch was launched in 2024 as an experimental 11-piece edition coming with a monochromatic grey-and-silver livery. 

In 2025, a new 22-piece edition came to light, featuring a blued ring around the perimeter of the dial and a blue fabric strap.

To be completely honest, exactly like Frank Geelen in his review for Monochrome, I personally "find fast-rotating foudroyante hands visually annoying and distracting". They really make me nervous, but this timepiece is quite fascinating nonetheless...

What about you: how do you feel about it?

Best, Emmanuel


A/ NANO FOUDROYANTE EWT (Experimental Watch Technology) - Limited to 11 pieces - 2024

White gold case with tantalum bezel and caseback ring




























credit: ch24.pl (1-2), Fratello (3-6), Scottishwatches (7-10) & Hodinkee


B/ NEW 2025 NANO FOUDROYANTE - Limited to 22 pieces

White gold case
















credit: The Eclecticum (1-3), @german_mean_time (4), Worn & Wound (5-7) & @shipoli_e 

The Nano Foudroyante EWT by SJX Watches




2025 Nano Foudroyante Review by Tim Mosso



Key Points from the Discussion

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The Discussion
M2
m2
Oct 10, 2025

It feels kind of boring and conservative compared to their usual over the top aesthetic (which I love)

BR
Bruno.M1
Oct 10, 2025

Spectacular Impressive Finished better than anything else But such a boring ugly watch. The dial, case, pushers and crown…. I really don’t like it

QU
quattro
Oct 10, 2025

even if I wasn’t expecting words like “boring ugly”. However having myself very conservative tastes, I like this dial and sober design quite a bit. As always, it’s just a matter of personal preferences and expectations. Best, Emmanuel

MA
Marc Obermann
Oct 10, 2025

I think I prefer the original Nano Foudroyante Experimental Watch Technology over the second one but both are quite fascinating and beautiful watches. Marc

M2
m2
Oct 10, 2025

But it doesn't really matter anyways since I can't afford an $800,000 watch lmao

QU
quattro
Oct 10, 2025

And I guess it’s because it’s am un-GF model that I like it, as I usually don’t respond to their louder pieces.

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