Greubel Forsey presents the first official limited edition of the Nano Foudroyante available to just 22 collectors worldwide.
Born from over a decade of research and the crucible of Experimental Watch Technology (EWT), the Nano Foudroyante has transcended its prototype origins. What began as Greubel Forsey’s most radical concept is now a fully independent timepiece: the 10th Fundamental Invention, matured and destined for connoisseurs who collect not only watches, but milestones in horology.
For this debut limited edition, the Nano Foudroyante is crafted entirely in white gold, affirming its status as a definitive, standalone creation. The dial architecture has evolved: rhodium-plated gold, a blue minute track, blued steel hands, and a crisp white foudroyante subdial with transferred numerals. The design achieves both heightened legibility and striking visual harmony, punctuated by a textured blue rubber strap — a deliberate aesthetic evolution from its commemorative predecessor.
At its heart lies nanomechanics: a disruptive approach to energy management within a mechanical watch. The foudroyante complication operates at just 16 nanojoules per jump—a reduction by a factor of 1,800 compared to traditional mechanisms. This allows the red-treated, ultra-light foudroyante hand to divide each second into six precise segments, powered directly by the 3 Hz balance wheel without reliance on a traditional gear train.
The Nano Foudroyante mechanism resides within Greubel Forsey’s first flying tourbillon, a technical and aesthetic centerpiece. Remarkably, the foudroyante dial remains permanently oriented to 12 o’clock, ensuring perfect readability as the tourbillon rotates.
Comprising 428 components (including 142 in the tourbillon cage), this hand-wound movement integrates two patents yet measures just 31.60 mm across — housed within a 37.90 mm white gold case, the most compact in Greubel Forsey’s history. Finishing details include a high-domed sapphire crystal, straight-grained caseband, transparent caseback, and hand-hammered inscriptions in polished relief: Nano Foudroyante and Greubel Forsey.
This is not a commemorative experiment, but a fully realised timepiece, the most energy-efficient, compact, and conceptually advanced Greubel Forsey creation to date. With production limited to just 22 pieces, the Nano Foudroyante is a collector’s opportunity to secure not only a watch, but a landmark in the evolution of mechanical horology.
Technical Specifications:
Nano Foudroyante
In white gold
Limited Edition
Hand-wound chronograph movement with 2 patents
Flying tourbillon with Nano Foudroyante • hours and minutes • small seconds • 60-second tourbillon rotation • chronograph seconds (trotteuse) • 60-minute counter • flyback function
MOVEMENT
MOVEMENT DIMENSIONS
• Diameter: 31.60mm
• Thickness: 9.40mm
NUMBER OF PARTS
• Movement: 428 parts
• Tourbillon cage: 142 parts
• Weight of the cage: 0.835g
NUMBER OF JEWELS
• 53
• Olived-domed jewels in gold chatons
CHRONOMETRIC POWER RESERVE
• One full day, with chronograph engaged
BARRELS
• Fast rotating barrel (1 turn in 3.7 hours) with a fixed main spring bridle
BALANCE WHEEL
• Variable-inertia with gold mean-time screws (10mm diameter)
FREQUENCY
• 21’600 vibrations/hour
BALANCE SPRING
• Phillips terminal curve
• Geneva-style stud
BRIDGES AND MAIN PLATES
• Nickel silver, frosted and spotted with polished bevelling and countersinks, straight-grained flanks, nickel-palladium treatment
• Straight-grained and flat black polished steel chronograph mechanism, polished bevelling, straight-grained flanks
• Three-dimensional column wheel, frosted and circular-grained, polished columns
• Central seconds wheel, circular-grained, polished bevelling with relief-engraved texts
• Gold plate, circular-grained, with engraved limitation number
TOURBILLON
• Flying Tourbillon with embedded Nano Foudroyante mechanism
• Foudroyante dial, constant vertical indication
• Titanium cage bridges, polished bevelling, straight-grained flanks, with engraved GF logo
• Platinum counterweight
GEARING
• Involute circle profile
• Micro-module with reduced play
DISPLAYS
• Hours and minutes
• Small seconds
• 60-second tourbillon rotation
• Foudroyante, sixth of a second
CHRONOGRAPH
• 60-second flange
• 60-minute counter, semi-instantaneous
EXTERIOR
CASE
• In white gold with high domed synthetic sapphire crystal
• Hand-polished bezel, caseband with hand-finished straight-graining
• Transparent back with high domed synthetic sapphire crystal
• Raised polished engraving “Nano Foudroyante” and “Greubel Forsey” on a hand-punched background
• Gold security screws
CASE DIMENSIONS
• Caseband diameter: 37.90mm
• Bezel diameter: 38.30mm
• Case height: 10.49mm
• Height on synthetic sapphire crystals: 14.34mm
WATER RESISTANCE OF THE CASE
• Water-resistant 3atm – 30m – 100ft (standard NIHS 92-20/SN ISO 22810:2010)
CROWN AND PUSHERS
• Crown with pusher, in white gold, engraved GF logo
• Pusher in white gold, hand-polished
DIAL
• Multi-level in gold, rhodium-coloured, minute-circle with blue finish, small seconds and chronograph minutes counter with polished bevel, engraved and lacquered indications, with a visual opening for the tourbillon
• Foudroyante in light alloy, polished bevel with flat black polished central plate.
HANDS
• Hours and minutes in polished blued steel with Super-LumiNova, hand-polished countersink, flat black polished head
• Small seconds and chronograph hands in polished blued steel, hand-polished countersink, flat black polished head
• Tourbillon and Foudroyante in light alloy, red treatment
STRAP AND CLASP
• Hand-sewn textured rubber
• White gold pin buckle, hand-engraved GF logo
Price upon request
For more information please visit Greubel Forsey