Having teased the launch of its eighth “fundamental invention” earlier this summer, Greubel Forsey has unveiled the Tourbillon Cardan featuring a 16-second inclined tourbillon suspended by a set of cardans, otherwise known as universal joints or gimbals. And for the nerds: the tourbillon is suspended in a mechanised gimbal that makes a fixed oscillation driven by the tourbillon, rather than a free-swivelling gimbal with differential gearing.
Despite a recent focus on sport watches, the Tourbillon Cardan is a reminder that no one does oversized, over-engineered watches quite like Greubel Forsey. The Tourbillon Cardan feels like a bridge between the past and future of the brand, suggesting the Tourbillon Cardan has been in development for several years.
The dynamic and visually compelling nature of the tourbillon, the large sizing, and the traditional form of the case recall the Greubel Forsey of years past, while the minimalist aesthetic and the choice of titanium for the case material are clear hallmarks of the brand’s future trajectory.
Impressive as it is, the swivelling tourbillon is not entirely a new idea. Zenith once had a double-axis gimballed escapement in its catalogue that was more complex than the Tourbillon Cardan but suffered from so-so reliability due to that very complexity.
Greubel Forsey has approached the gimbals in a more concise manner, with the gimbals oscillating in a fixed motion that is being by the rotation of the tourbillon. This does away with the free-swivelling aspect that calls for differential gearing, so this execution appears to be far more sound in terms of functionality but also simpler.
At CHF470,000, the Tourbillon Cardan is positioned near the top of Greubel Forsey’s current collection. At this level, “value” is not the first word that comes to mind but as an expression of maximalist technical watchmaking, watches like the Tourbillon Cardan have few peers. Though not strictly a limited edition, output will be limited to 11 pieces per year over the next five years.
The 8th “fundamental invention”
Impressive both technically and aesthetically, the Tourbillon Cardan is substantial in size. It has a titanium case that measures 46 mm at the bezel, and is 18.15 mm thick including the domed sapphire crystal (the height of the case is 13.81 mm thick).
And of course the Tourbillon Cardan is finished in the Greubel Forsey house style, which is a marriage of traditional methods and contemporary aesthetics. Though monochrome in its appearance, the movement offers a satisfying range of contrasting textures, from the hand-frosted titanium mainplate to the barrel-polished arch over the tourbillon cage; this arch alone requires 30 hours of hand finishing.
The raison d’être of the large watch, however, is what the brand calls its eighth fundamental invention: a pair of cardans arranged at 90° that tilt backwards and forwards every 48 seconds, driven by the rotation of the tourbillon, to optimise the position of the brand’s signature 30° high-speed tourbillon.
Unlike conventional gimbals, which keep an object horizontal, the cardans oscillate between +30° and -30° and are synchronised to the position of the tourbillon. Since the upper tourbillon bridge is mobile, tilting back and forth in the cardans, it gives the Tourbillon Cardan a distinctive aesthetic that calls to mind the brand’s first fundamental invention, the Double Tourbillon 30º.
Force and finesse
With any new technical innovation in watchmaking, it’s reasonable to question the real-world benefits. In other words, do the gains in timekeeping performance make up for the additional complexity? Tourbillons, in particular, add inertia to the system, draining energy that could otherwise be allocated to a heavier or higher-frequency oscillator. With a fast-rotating cage, these effects are compounded.
The brand has overcome this challenge with both force and finesse. In terms of force, the engineers at Greubel Forsey have packed four co-axial series-coupled mainspring barrels to deliver stable energy for 80 hours. These barrels are fast-rotating, making one full turn every 2.7 hours. This reduces mainspring adhesion, resulting in smoother power delivery. As is characteristic of the brand’s movements, one barrel is equipped with a slipping mainspring to prevent accidental damage due to over-winding; a welcome safety feature.
In terms of finesse, the tourbillon cage has been slimmed down to just 0.92 grams; an impressive figure given it contains the large 12.6 mm balance wheel developed for the Signature 1. Made in-house to the brand’s own design, the proprietary balance wheel offers inertia of 18.9 mg.cm2, good for a healthy 198 microwatts of balance power.
While we don’t yet have verified timekeeping data for the Tourbillon Cardan, the movement’s technical characteristics are very promising and suggest a capacity for outstanding real-world performance. Furthermore, Greubel Forsey takes chronometry seriously, winning the short-lived Concours de Chronométrie in 2011 with a similarly complicated watch.
Key facts and price
Greubel Forsey Tourbillon Cardan
Diameter: 46 mm
Height: 13.81 mm (18.15 mm including crystal)
Water resistance: 30 m
Movement: Tourbillon Cardan
Functions: Hours, minutes, seconds, and power reserve
Winding: Manual wind
Frequency: 21,600 beats per hour (3 Hz)
Power reserve: 80 hours
Strap: Vegan leather with titanium folding clasp
Limited edition: No, but production is limited to 11 pieces per year
Availability: Through Greubel Forsey retailers and direct from the brand
For more, visit Greubel Forsey.
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