Tourbillon Cardan

The Tourbillon Cardan is designed to reach new heights of chronometric precision. It combines three 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. For Greubel Forsey, this was not the end, but the very beginning.

While most tourbillons have a revolution of 60 seconds, that of the 8th Fundamental Invention is almost four times faster. Just 16 seconds. This is the fastest yet for a Greubel Forsey tourbillon. It moves through more positions in less time, and therefore offers a much higher average performance.

What's more, this tourbillon 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 it was conceived over two centuries ago, was designed for pocket watches worn vertically. For a wristwatch, its design needed to be totally rethought, optimised 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.

The Tourbillon Cardan has four barrels. This is a remarkable construction at Greubel Forsey (occurring just once in 20 years). They are coaxially stacked, 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 maybe outside the rigorous Greubel Forsey precision tolerances.

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.