====== Greubel Forsey Tourbillon Cardan ======

{{wst>image_cr|Greubel Forsey|Tourbillon Cardan}}
{{wst>image_cr|Greubel Forsey|Tourbillon Cardan back}}

The **Tourbillon Cardan** is a wristwatch from [[Greubel Forsey]].

Named after its [[complication]], the Tourbillon Cardan combines three principles:

  * First, while most [[tourbillon]]s complete one rotation every 60 seconds, the brand's eighth great invention rotates almost four times as fast. It takes just 16 seconds. This is the fastest rotation time of a tourbillon from Greubel Forsey to date. It runs through more positions in less time and therefore offers a significantly higher average performance.\\ In addition, this tourbillon is the first to feature a large balance wheel developed and manufactured in-house by Greubel Forsey. It takes advantage of the outstanding balance of its masses, its size (12.6 mm) and its optimized oscillations. Its high inertia also makes it less sensitive to vibrations and speed variations.

  * Second principle: the 30° angle. The tourbillon - as it was conceived over two hundred years ago - was intended for pocket watches worn vertically. For wristwatches, the concept had to be completely rethought, optimized for the positions of everyday life in the 21st century.

  * Third principle: This high-speed tourbillon, inclined at an angle of 30°, is guided by two moving rings connected by two 90° axes. These rings tilt back and forth in 48 seconds. Although the design is reminiscent of gimbals, it is very different, as the two rings can move freely and their task is to keep the object they hold horizontal. In the Tourbillon Cardan, the inclination of the rings is controlled between +30° and -30°, while the inclination of the tourbillon is also 30° but never varies. This improves the relationship between angular velocity and chronometric performance.

The Tourbillon Cardan has four coaxially stacked [[barrel]]s. 

As the tourbillon cannot be held in place by a fixed upper bridge, this function is performed by the two arched cardan rings. 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.

A series of unique finishes were developed especially for this timepiece. The movement plates were crafted from frosted [[German silver]] with polished bevels and straight-grained flanks, while the titanium mainplate features a large polished angle as a backdrop for the suspension. The upper bridge of the tourbillon cage is made of satin-finished titanium with straight-grained flanks and polished bevels, above and below.

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.

The Tourbillon Cardan will be available with a 45.5 mm titanium case.

Greubel Forsey plans to produce only 55 examples of the caliber over the next five years.

<WRAP ud ud_mod>
**Movement:**
  * [[Manual winding]] [[manufacture movement]], 21,600 A/h
  * [[Tourbillon]], patented, with 
    * ultra-fast inner tourbillon cage (1 rotation in 16 seconds) in titanium, barrel-polished and hand-bevelled, inclined at a 30° angle with gold counterweight
    * outer flying Cardan cages, 48-seconds cycle, double variable tilt at 30°, polished and hand-bevelled, straight-grained flanks
  * 49 [[jewels]], olived-domed jewels in gold [[chatons]]
  * Hairspring with [[Phillips terminal curve]]
  * Movement: 389 components
  * Cardan tourbillon cages: 98 components
  * Four coaxial series-coupled fast-rotating [[barrel]]s (1 turn in 2.7 hours)
  * [[Power reserve]] 80 h

**Case:**
  * [[Titanium]]
  * Ø 46 mm, H 13.81 mm
  * [[Sapphire crystal]] domed and transparent, high-domed caseback
  * [[Waterproof]] to 3 bar

**Dial:**
  * Multi-level gold dial with openworked pillars, circular-grained with engraved and lacquered minute-circle, polished flanks
  * Gold hour markers
  * Small seconds and power-reserve indicators in gold, engraved and lacquered

**Functions:**
  * Hours, minutes, [[small seconds]]
  * [[Power reserve indicator]] on a sector

**Wristband:**
  * Non-animal material, hand-sewn
  * Titanium [[folding clasp]]

**Limited edition:**
  * 55 pieces in the next five years
</WRAP>


{{tag>Watch_models Watches_with_tourbillon Greubel_Forsey_models}}