Greubel Forsey - Tourbillon Cardan

Greubel Forsey unveiled the Tourbillon Cardan, its 8th Fundamental Invention. The price of the Greubel Forsey Tourbillon Cardan is CHF 470,000

For many years, Greubel Forsey has been working on the development of a new type of tourbillon. Over the past three years, this tourbillon has evolved from concept to reality and is now revealed as the 8th Fundamental Invention by the Atelier.

Designed to reach new heights of chronometric precision, the new Tourbillon Cardan combines three main principles. 

The first: the tourbillon. The mechanism patented by Abraham-Louis Breguet in 1801 was designed to compensate for the differences in rate, in vertical positions (you can read the history of this watchmaking feat here). Unlike most tourbillons that have a 60-second revolution, the 8th Fundamental Invention's revolution is nearly four times faster. Just 16 seconds. This is the fastest yet for a Greubel Forsey tourbillon. It moves through more positions in less time, consequently providing significantly higher average performance.

This tourbillon also incorporates, for the very first time, the large balance wheel designed, developed and made in-house by Greubel Forsey. It benefits from the exemplary balance of its masses, its large size (12.6 mm) and its optimised oscillations. Its high inertia also makes it less sensitive to shocks and variations in speed.

Second principle: the 30° angle. The tourbillon, as conceived over two centuries ago, was designed for pocket watches worn vertically. For a wristwatch, its design needed  complete rethinking, tailored for the positions adopted in everyday 21st-century life.

Third principle: this 30° high-speed tourbillon is guided by two mobile rings, linked by two 90° axes. In 48 seconds, they tilt backwards and forwards. This construction may seem reminiscent of gimbals, but is very different from a traditional gimbal where the two rings are free to move and their job is to keep the object they contain horizontal. In the Tourbillon Cardan, the tilt of the rings is controlled (+30° to -30° range), while the degree of inclination of the tourbillon is inclined (also 30°) and never varies, offering a better ratio of angular velocity to chronometric performance.

As the tourbillon cannot be held in place by a fixed upper bridge, this function is performed by the two arched cardan rings. Without adopting the traditional construction, Greubel Forsey's 8th Fundamental Invention creates a new type of tourbillon with a flying appearance, which is both original and patented. A seemingly complex construction but with a very small number of components, it offers an open, airy aesthetic that leaves the eye free to admire its kinematics.

The Tourbillon Cardan has four barrels, coaxially stacked and with a slipping mainspring to prevent excess tension during winding. They offer 80 hours of chronometric power reserve. Beyond that point, the timepiece still runs very well, but outside the rigorous Greubel Forsey precision tolerances.

As it is easy to imagine, finishes are of the highest standards and some of them have been developed specifically for this timepiece. 

The movement plates are in frosted nickel silver, with polished bevels and straight grained flanks while a titanium mainplate presents a large polished flank as a backdrop to the cardan. 

The upper bridge of the tourbillon cage is made of frosted titanium with straight grained flanks and polished bevels, above and below. The arch is barrel-polished. It takes more than 30 hours to finish this single component.

The cardan’s rings are matt finished, with polished bevels and straight grained flanks, while the lower plate is frosted by hand, a task that requires a particularly special expertise from the Atelier Manufacture. 

Finally, there are two dials (hours/minutes and seconds), one circular grained with polished flanks and a very large mirror finish angle, the other with a polished exterior flank.

Greubel Forsey has additionally created a high-domed sapphire crystal for this piece. It houses the full height of the tourbillon and cardan system, offering a highly architectural technical vision. 

The Tourbillon Cardan will be available in a 45.5 mm x 13.81 mm (or 18.15 mm including the sapphire crystals) titanium case. This metal was chosen for its modernity and lightness, in keeping with the airy aesthetic of the Cardan tourbillon. Water resistance is ensured up to a pressure of 3 bar.

Greubel Forsey plans to build just 55 pieces of the Tourbillon Cardan over the next 5 years, 11 per year. The price is CHF 470,000. greubelforsey.com

Video clip courtesy by Michel Nydegger (Instagram: @michelknydegger)