Swiss luxury watch brand Greubel Forsey presents the Double Tourbillon Asymétrique, a reinterpretation of Robert Greubel and Stephen Forsey’s first Fundamental Invention, the Double Tourbillon 30°, featuring an asymmetric case marking a striking departure from how this complication has been previously presented.
In harmony with its distinctive design, the power reserve is indicated by a rotating disk, underlining the highly original nature of this timepiece. The Double Tourbillon Asymétrique is available in a unique edition comprising 11 pieces in white gold and 11 pieces in 5N red gold.
Greubel Forsey launched the Double Tourbillon 30° Vision in 2004, now, nearly a decade later, this new interpretation features an asymmetric positioning of the Double Tourbillon 30°; which has only previously been presented symmetrically in the collection. To achieve this, the movement architecture has been completely reconstructed, with the outer cage of the patented Double Tourbillon 30° inversed. However, the one‐minute rotation of the inner tourbillon cage and the four‐minute rotation of the outer tourbillon cage remain the same.
The movement is housed in a 43.5 mm diameter case with a curved lateral window in the case band at 8 o’clock. This three‐dimensional opening offers the observer a very special view of the double tourbillon system, showcasing the complexity and aesthetic qualities of this unique complication.
The black treatment of the mainplates, forming the backdrop for the tourbillion system accentuates the three‐dimensionality and depth of the double cages, which are composed of no less than 130 components. The polished conical arm and the flat black polish of the steel tourbillon bridge is one example of Greubel Forsey’s signature superlative hand finishing.
The power reserve indicator at 2 o’clock features an innovative rotating disk displaying optimal remaining running time by means of a fixed red triangle instead of a conventional hand.
The architecture of the gold dial contributes to the perfect balance of the timepiece. The minute ring is concentric around the satin‐finished hour display, with the applied polished gold hour indexes creating additional contrast and relief. In the white gold version, the dial is finished in shades of grey, anthracite and black, while the dial of the red gold version is treated in black and anthracite. The hands and indexes are in perfect harmony with their case – white gold or in red gold, depending on the version. For ideal legibility at night, the tips of the hour and minute hands have been filled with luminous material.
The individual number of each timepiece is engraved on a gold plate concentric to the power reserve indicator. The small seconds at 6 o’clock features a striking triangular red hand, one of three bright red details on the dial. An asymmetric domed sapphire crystal display back mirroring the lines of the case reveals the beautiful movement beneath. The nickel‐palladium treated frosted and bevelled geartrain bridge juxtaposes against the sobriety of the black‐chromed mainplate.
The polished internal angles of the beautifully finished one‐piece gear ‐train bridge bear testimony to the meticulous hand finishing throughout the timepiece. This bridge, fixed by four blued‐steel screws, supports two white gold plates: one with the individual number of the timepiece mirroring that on the power reserve indicator; the other signed ‘Greubel Forsey’. With their golden finish against a black background, the two series configured mainspring barrels and centre wheel stand out visually from the black mainplate.
Presented in a unique edition of 11 pieces in white gold and 11 pieces in 5N red gold, the Double Tourbillon Asymétrique is an exclusive and original addition to the Greubel Forsey collection. The timepiece is completed by a hand‐sewn alligator strap with folding clasp in the same colour gold as the case.
The manual‐winding movement comprises 326 components. It is powered by two rapidly rotating mainspring barrels in series, which provide a72‐hour reserve of optimal power. The Double Tourbillon 30° features a variable inertia balance with Phillips terminal curve beating at 3Hz/21,600 vibrations per hour – the inner and outer cages make one revolution in 1 minute and 4 minutes respectively. The inner cage is at a 30° angle to the outer cage.
The mainplates in nickel silver are frosted with straight grained flanks, hand polished countersinks and bevels, with a black chrome treatment, while the bridges are frosted, spotted, with hand polished countersinks and polished bevels with a nickel‐palladium treatment. The dial is in black‐oxidised or anthracite finished gold, with indications for hours, minutes and small seconds. The power reserve indicator is via a rotating disk. There are two hand‐finished gold plates engraved with the individual number of the timepiece: One on the dial side, the other visible through the display back.
The asymmetric case is available in white gold or 18K 5N red gold and measures 43.5 mm in diameter and 16.13 mm in height. It features asymmetric synthetic sapphire crystals on the dial side and for the display back, as well as a lateral window set into the case band, three dimensional, variable geometry shaped lugs, raised polished engraving “Greubel Forsey” on a hand‐punched background and gold security screws. The black alligator strap is hand stitched with a white gold or red gold folding clasp to match the case.
Like all Greubel Forsey timepieces, levels of finishing and decoration are executed without compromise. To provide optimal visual effect, all components of the movement are created according to architectural criteria that highlight a myriad of details revealing their beauty.
Elements of finishing such as spotting, frosting, straight‐graining, scintillating flat black mirror polishing, as well as the stunning hand finished bevels. The three‐dimensional architecture of this timepiece showcases its mechanisms and components and emphasizes the finishing and decoration, reflecting the extremely high standards of Greubel Forsey’s craftmanship.
Model: Double Tourbillon Asymétrique
11 pieces in white gold and 11 pieces in 5N red gold
Mechanical hand-wound movement with patented tourbillon
Calibre GF02a2 Movement
• Diameter: 36.40 mm
• Thickness: 9.48 mm
Number of parts
• Complete movement: 326 parts
• 2 tourbillon cages: 130 parts
• Weight of the two cages: 1.17 g
Number of jewels: 39, Olived-domed jewels in gold chatons
Power reserve: 72 hours
Barrels: Two series-coupled fast rotating barrels (1 turn in 3.2 hours), one of which is equipped with a slipping spring to avoid excess tension
Balance wheel: Free sprung variable-inertia balance with white gold mean-time screws (10.70 mm diameter)
Frequency: 21’600 vibrations/hour
Balance spring: Phillips terminal curve; Geneva-style stud
Main plates: Nickel silver, frosted with polished bevelling and polished countersinks, black chrome treatment
Bridges: Nickel silver, frosted, spotted with polished bevelling and polished countersinks, nickel-palladium treatment; Two gold plate engraved, one with the individual number and one with the text “Greubel Forsey”
Inner tourbillon: Inclined at a 30° angle, 1 rotation per minute
• 1 rotation in 4 minutes
• Hand-bevelled and openworked cage pillars
• Gold counterweight
• Involute circle profile
• Conical gearing with corrected profile
Hour and minute
72-hour sectorial power reserve on a disc
In white gold or 5N red gold with convex synthetic sapphire crystal
Transparent back with convex synthetic sapphire crystal
Raised polished engraving “Double Tourbillon” on a hand-punched background
Three-dimensional, variable geometry shaped lugs
Gold security screws
Hand-engraved individual number
Unique edition of 11 pieces in white gold and 11 pieces in 5N red gold
Diameter: 43.50 mm; Thickness: 16.13 mm
Water resistance of the case: 3 atm – 30 m – 100 ft (standard NIHS 92-20/SN ISO 22810:2010)
Crown: In white gold or 5N red gold with engraved and black lacquered GF logo
In gold, black oxidised
Hours, small second and power-reserve indicators in gold
1 engraved gold plate with the individual number
Applied gold Greubel Forsey logo
Hour and minute in polished gold with Super-LumiNova
Small second (red triangle)
Strap and clasp
Hand-sewn black alligator
18 k 5N red or white gold folding clasp, hand-engraved with the Greubel Forsey logo