According to high-end Swiss watchmaker Greubel Forsey, its novel “Nano Foudroyante” mechanism is a game-changer in mechanical timekeeping. Introduced to celebrate its 20th anniversary, the Greubel Forsey Nano Foudroyante EWT not only introduces the brand’s new foudroyante mechanism but also marks the brand’s first flying tourbillon and the first chronograph. But what’s special about the namesake nano foudroyante?
Rarely do brands discuss why they include a foudroyante mechanism in a watch, because the reality is that these days they are mostly for visual fun. We’ve seen foudroyantes or similar devices from Jaeger-LeCoultre, Zenith, and F. P. Journe, among others, and there’s always a feeling of, “That’s neat, but why?” A traditional foudroyante manifests itself with a very fast-moving hand that usually moves six positions in one second, depending on the operating frequency of the regulation system. Their purpose is often related to measuring the accuracy of a chronograph (a good example is the implementation on the Zenith El Primero Striking 10th models), but in this instance, the mechanism seems to run all the time and is not connected to the chronograph – which does exist in the watch. Greubel Forsey’s Nano Foudroyante hand rotates at the usual foudroyante rate, but the innovation is that the brand reduced its energy consumption by a factor of 1.8, allowing the mechanism’s size to be reduced by 90% according to company. Greubel Forsey has also created a novel system whereby the small foudroyante dial is mounted on the flying tourbillon and is geared such that it always remains “upright,” even with the spinning of the tourbillon. To place a foudroyante display that always remains upright on a spinning 60-second tourbillon cage was no doubt challenging, though it mainly advances the art of horology more so than the practicality of it.
Greubel Forsey is only producing 11 pieces of this version of the Nano Foudroyante and makes it clear that a watch like this is “Experimental Watch Technology,” hence the EWT in the name. By reducing the size of the foudroyante, the brand was able to use the smallest case it has ever produced, measuring several millimeters narrower than most of its timepieces. The case is only 37.9mm wide and 10.49mm thick, is water resistant to 30 meters, and comes on some unspecified “non-animal” strap material. And while it may be the smallest watch the brand has produced, it certainly won’t be the lightest: The case is made from 18k white gold with a tantalum bezel.
Greubel Forsey’s Nano Foudroyante EWT also has a chronograph, which it barely mentions as part of the Nano Foudroyante’s release. The 60-minute chronograph (operated with the 2 o’clock pusher and the crown pusher) has a central seconds hand and a subsidiary chronograph minute counter on the left side of the dial. Under that is a small dial that operates as a running second indicator. Notably (and not for the first time), Greubel Forsey has applied a red triangle indicator to the rotating tourbillon ring, though these are curiously not in sync in the press photos.
The movement is produced from 428 parts and operates at 3Hz (21,600 vph). One notable element here is the power reserve: Greubel Forsey only provides the power reserve with the chronograph engaged and says that is just 24 hours (“one full day”). That’s a far cry from GF’s typical 72 hours, as well as what most consumers expect these days. It isn’t clear what the power reserve of the Nano Foudroyante watch is without the chronograph running, but it wouldn’t be much longer. It’s probably important to remember that this watch is explicitly “experimental,” and as such, may be better thought of as a proof of concept than the final product. The movement is, of course, finished to the brand’s exceptionally high standards.
In many ways, the Nano Foudroyante EWT tourbillon watch is innovative and interesting to talk about. It captures the essence of Greubel Forsey while offering both a new movement and a new wearing experience. True to the name, the watch is experimental, and thus meant for enthusiasts who want to try new (and very expensive) things. It isn’t the most refined or high-performance Greubel Forsey around, nor is it clear what practical performance benefits the movement has. That said, the visual movement of the dial should be very impressive, especially with the chronograph running and all the hands moving at seemingly different rates. Greubel Forsey will only make 11 pieces of this version of the Nano Foudroyante EWT with the 18k white gold and tantalum case with the silver dial. My suspicion is that there will be a few more versions before this concept exits the experimental phase. The Greubel Forsey Nano Foudroyante EWT watch is priced at CHF 465,000. Learn more at the Greubel Forsey website.
