GREUBEL FORSEY – CONVEXE Double Balancier Convexe 43.5 mm Titanium Edition 2023
DOUBLE BALANCIER CONVEXE:
A SCULPTURE OF TIME
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Greubel Forsey unveils its Double Balancier Convexe in a new diameter of just 42.5 mm. This new creation, in titanium, will be made as a limited edition of only 88 pieces and offers an unprecedentedly modern and architectural perspective of its Double Balancier movement and constant spherical differential.
FIFTEEN YEARS IN THE MAKING
The popular belief is that a watchmaking company produces its movements, then its cases, for which it defines the diameter that it feels best meets its customers' expectations. Nothing could be further from the truth at Greubel Forsey.%20&%20Double%20Balancier%20Convexe%20(42.5%20mm)_4776_.jpg)
At the Atelier Manufacture, each timepiece is designed exclusively following the principle of unique creative process, "one calibre - one case". They are inseparable. They are created for each other, from the first sketch to the final assembly.
This is particularly true of the Convexe collection. Its fundamental identity is based on the distinctive architecture of its double-curved case, which hugs the wrist perfectly. Its design evokes the construction of the movement that unfolds in three dimensions and emphasises its profile.
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A very limited inaugural series The guiding idea behind this new diameter is, once again, to push back the limits, even those already set by Greubel Forsey: how to create a more compact timepiece while preserving the harmony of its proportions and the architectural requirements of the movement.
To meet this challenge, Greubel Forsey had to rethink the construction of the movement and enhance its finish - only possible thanks to the high level of expertise at the Greubel Forsey workshops, where each timepiece is entirely assembled and finished by hand.
This allows the Atelier's artisans to adapt their art, piece by piece, according to the specifics of each collection. The 42.5 mm Double Balancier Convexe edition will comprise only 88 timepieces, available between 2023 and 2026.
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In-depth work The inaugural Double Balancier Convexe was presented in 2022 and was not then designed for a diameter of 42.5 mm. Underlining the disruptive nature of this creation, this reduction in diameter is particularly significant, taking note that the tolerances of a Greubel Forsey timepiece are adjusted to the micron. Averted collectors will fully appreciate this fact.
The smaller volume of the new 42.5 mm-diameter case houses the Double Balancier, the sixth Fundamental Invention from Greubel Forsey. Its prototype, patented in 2007, has continued to evolve ever since. It was first offered as an EWT (Experimental Watch Technology) prototype, in which the two regulating organs were superimposed and inclined at 20°. A second evolution of six pieces followed close behind, with the two regulating organs positioned on three-dimensional and inclined planes, this time at 35°.
In 2016, Greubel Forsey presented the Double Balancier movement in its current form: the two balance wheels, both inclined at 30°, optimise performance, especially in stabilised positions, while the Constant Spherical Differential generates greater amplitude stability.
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Preserving lines and comfort Its new 42.5 mm diameter makes it possible to approach the Convexe case with a new configuration. Mathematically, with a smaller diameter, its curves should have been steeper. But the Greubel Forsey teams have reworked the convex profile, which is unique in the world, adapting its precise angles and proportions, rather than simple homothety.
The new case has been completely redesigned to provide optimum comfort on the wrist and maintaining Greubel Forsey’s own expectations for ergonomics and excellence.
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TECHNICAL DETAILS
Double Balancier Convexe in titanium Limited edition
Hand-wound movement with 2 patents
Double Balancier • hours and minutes • small seconds •
4-minutes spherical constant differential rotation • power-reserve
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Movement
Movement dimensions
• Overall diameter: 37.70 mm
• Thickness: 9.46 mm
Number of parts
• Movement: 371 parts
• Escapement platform: 2 x 70 parts
• Spherical constant differential: 30 parts
Number of jewels
• 50
• Olived-domed jewels in gold chatons Chronometric power reserve
• 72 hours
Barrels
• Two coaxial series-coupled fast-rotating barrels (1 turn in 3.2 hours), one of which is equipped with a slipping spring to avoid excess tension
• Relief-engraved text, circular-grained, black treatment,
polished chamfer
Balance wheel
• Variable-inertia with gold mean-time screws (10 mm diameter)
Frequency • 21’600 vibrations/hour
Balance springs
• Phillips terminal curve
• Geneva-style stud
• Anti-shock system with gold pin
Bridges and main plates
• Titanium
• Frosted, polished bevelling and countersinks, grey treatment
• Multi-level, openworked centre bridge, polished bevelling and countersinks
Movement side
• Flat black polished steel differential bridge
• Gold plate with engraved limitation number, circular-grained, polished bevelling and countersinks, straight-grained flanks
Escapement platforms
• Inclined at a 30° angle
• Steel, straight graining, hand-polished bevelling and countersinks
• Polished steel pillars
• Openworked steel balance wheel bridges, hand-polished bevelling and countersinks, flat black polished
Gearing
• Involute circle profile
• Inclined gear with profiled teeth on fourth wheel
Displays
• Hours and minutes
• Small seconds
• 4-minutes spherical constant differential rotation
• Power reserve on a sector
Exterior
Case
• Titanium with curved synthetic sapphire crystal
• Three-dimensional, variable geometry-shaped bezel, hand-polished with hand-finished straight graining
• Profiled lugs, screwed fixing
• Transparent back with curved synthetic sapphire crystal
• Titanium security screws
• Raised engraving “Double Balancier” and “Greubel Forsey”
Case dimensions
• Caseband diameter: 42.50 mm
• Bezel diameter: 44.40 mm
• Case height: 13.75mm
• Height on synthetic sapphire crystals: 14.35 mm
Water resistance of the case
• Water-resistant 10 atm - 100 m - 328 ft (standard NIHS 92-20/SN ISO 22810:2010)
Crown
• Titanium, polished, frosted and straight-grained, with GF logo
Dial side
• Three-dimensional, variable geometry hour-ring with engraved and lacquered minute-circle
• Three-dimensional, variable geometry hour indexes, polished, with Super-Luminova
• Power-reserve indicator, engraved and lacquered
• Differential rotation and small seconds indicators in gold
Hands
• Hours and minutes, curved profile, polished steel with Super-Luminova
• Power-reserve, 4-minutes and small seconds in polished steel, blued according to the version, flat black polished head
Strap and clasp
• Non-animal material, rubber with texture in relief, titanium folding clasp, engraved GF logo
• On demand:
3-row metal bracelet in titanium, folding clasp with integrated fine adjustment, engraved GF logo
Limitation
Limited Edition of 88 pieces.
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Press Release - 2023
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GREUBEL FORSEY SA
For further information:
Communication Department
press@greubelforsey.com – +41 79 194 2884
Eplatures-Grise -16 P.O. Box 670
2301 La Chaux-de-Fonds - Switzerland
+41 32 925-4545
+41 32 925-4502
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