Greubel Forsey is one of the brands that keep the horological game at the highest niveau. The world of watches is richer and more powerful every year with their pieces. Since 2004, when Robert Greubel and Stephen Forsey teamed up, their brand produced only bold high-end horological pieces. Not only an exceptional quality of finishes but also innovations elevated at the level of art. For SIHH 2018, Greubel Forsey makes no exception in fine watchmaking and presents the Greubel Forsey Différentiel d’Égalité.
Greubel Forsey Différentiel d’Égalité is the first brand’s watch with integrated dead-beat second
Greubel Forsey Différentiel d’Égalité
The Différentiel d’Égalité is the fifth main invention of the Greubel Forsey duo. It was first presented at Baselworld 2008 as part of the EWT Laboratory. A more advanced version was unveiled at SIHH 2010. The goal of the invention is to make a steady power distribution from the mainspring barrel to the regulator. The regulating organ maintains during all 60 hours of power reserve a constant balance amplitude.
“The Différentiel d’Egalité is based on a spherical differential that receives energy from the mainspring barrel and releases it in constant amounts to the regulating organ. In order to maintain this constant rate, the mainspring barrel powers a secondary spring, which is rewound every five seconds. Placed before the regulating organ, the spring ensures a uniform transmission of energy by eliminating power variations from the mainspring barrel and correcting variations in torque generated by the gear train.” – 2008 Différentiel d’Egalité invention, Greubel Forsay Website
Greubel Forsey Différentiel d’Égalité reveals on the dial the 30° inclined balance wheel and part of the movement, the dead-beat second complication, the power reserve and, of course, the time.
The 44m diameter white gold case is covered with a high domed sapphire crystal to give a note of a refined silhouette. A large opening in the dial reveals the beauty of the movement.
Greubel Forsey Différentiel d’Égalité is the first timepiece of the reputable brand with a dead-beat second. This desired complication offers, beside the poetic significance, an increased precision in reading but also in setting the watch. Pulling the crown results in a stop of the balance wheel and a reset of the seconds. The system ability of so precise set is shadowed only by the imposing movement’s finishes. The heart and the hammer of the stop&reset mechanism are visible on the back of the watch along with the engraved inscriptions of the key values that Robert Greubel and Stephen Forsey instil in their timepieces.
Another great feature of this calibre is the 30° inclination of escapement, respectively balance wheel. This angle minimizes the negative influence of the gravity. The escapement and the dead-beat seconds can be admired on the front, as part of the dial.
Greubel Forsey Différentiel d’Égalité presents on the back an engraved list with all values the brand stands for. From the movement is visible the stop&reset system.
Greubel Forsey Différentiel d’Égalité Specifications and Price
Greubel Forsey Différentiel d’Égalité will have a price of CHF265,000, without taxes. Limited edition of 33 pieces in white gold with hand-wound movement with patented spherical Différentiel d’Égalité.
Functions: Spherical Différentiel d’Égalité • inclined fixed escapement • hours and minutes • dead-beat seconds • small seconds • power-reserve • stop balance and reset on dead-beat seconds.
Movement
Movement dimensions
• Diameter: 36.40 mm
• Thickness: 9.99 mm
Number of parts
• Movement: 359 parts
• Inclined fixed escapement: 71 parts
Number of jewels
• 47
• Olived-domed jewels in gold chatons
Spherical Différentiel d’Égalité
• 24 parts including 4 jewels and 3 satellites
• Differential cage, circular-grained, polished bevelling and countersinks, straight-grained flanks
• Uniform torque, rewinding once per second with integrated spring
Chronometric power reserve
• 60 hours ± 10%
• Optimized amplitude over the entire power reserve
• Stop work mechanism
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
• Barrel with relief engraving “Greubel Forsey”
Balance wheel
• Variable-inertia with gold mean-time screws(10 mm diameter)
Frequency
• 21’600 vibrations/hour
Balance spring
• Phillips terminal curve
• Geneva-style stud
Main plate
• Nickel silver, frosted and spotted with polished bevelling and countersinks, straight-grained flanks, nickel-palladium treatment
Bridges
• Nickel silver, frosted and spotted with polished bevelling and countersinks, straight-grained flanks, nickel-palladium treatment
• Flat black polished gold plate with raised engraved text, polished bevelling and countersinks, straight-grained flanks with gold chatons
• Circular-grained gold plate with individual number, polished bevelling and countersinks, straight-grained flanks
Reset mechanism
• Stop balance and reset activated by crown
• Flat black polished steel reset mechanism, polished bevelling, straight-grained flanks
Inclined fixed escapement
• Inclined at 30°
• Flat black polished steel lower bridge, polished bevelling and countersinks, straight-grained flanks
• Polished steel pillars
• Flat black polished steel balance wheel bridge, barrel-polished, polished bevelling and countersinks, straight-grained flanks
Gearing
• Involute circle profile
• Spherical Différentiel d’Égalité with conical gearing
• Conical profiled teeth for inclined fixed escapement
Displays
• Hours and minutes
• Dead-beat seconds
• Small seconds
• 60-hours power reserve on a sector
Exterior
Case
• In white gold with high domed synthetic sapphire crystal
• Transparent back with synthetic sapphire crystal
• Three-dimensional, variable geometry-shaped lugs
• Raised polished engraving “Différentiel d’Égalité” and “Greubel Forsey” on a hand-punched background
• Gold security screws
• Hand-polished bezel, caseband with hand-finished straight graining
• Hand-engraved individual number
Case dimensions
• Diameter: 44.00 mm
• Height: 15.30 mm
Water resistance of the case
• Water-resistant 3 atm – 30 m – 100 ft (standard NIHS 92-20/SN ISO 22810:2010)
Crown
• In white gold with engraved and black lacquered GF logo
Dial side
• Multi-level synthetic sapphire hour-ring, lacquered galvanic growth hour indexes, engraved and lacquered minutes and dead-beat seconds
• Small seconds and power-reserve indicators in gold, engraved and lacquered, hand matt lapped
Hands
• Hours and minutes in gold with Super-LumiNova
• Small seconds, dead-beat seconds and power-reserve in polished blued steel, hand-polished countersinks
Strap and clasp
• Hand-sewn alligator
• White gold folding clasp, hand-engraved with the GF logo
1 Comment
It’s kind of ironic the word égalité is used in connection with GF. Maybe their new slogan will be “watches for the people?”