North America Exclusive: Double Balancier Sapphire

The Double Balancier Sapphire was inspired by the phenomena of transparency and light. Within a case entirely crafted from sapphire crystal, the spectacular workings of the mechanism are revealed from every angle. The timepiece’s elegant open architecture enhances its components to unveil a stirring, visually striking spectacle.

When founding Greubel Forsey, Robert Greubel and Stephen Forsey focused all their energy on research and development, with the objective of improving the performance of their timepieces. Their efforts gave rise to many fundamental watchmaking advancements, which took concrete form as inventions, focusing particularly on chronometry.

The Double Balancier – Greubel Forsey’s sixth Fundamental Invention – is a phenomenal timepiece in many ways. Its principle: to drastically enhance timekeeping precision.

Robert Greubel and Stephen Forsey began exploring the Double Balancier – i.e. two fixed oscillators positioned along two different axes at precise predetermined angles – more than 10 years ago in order to improve the average timing rate in stable positions. Thanks to the combined effects of the constant spherical differential and the angle of the balances, the effects of gravity are minimized by halving the margin of error and maximizing timing precision, a development which resulted in two patents.

Light floods into the timepiece through its sapphire crystal case, which alone required over 900 hours of machining. This showcases the three-dimensional architecture from every angle and reveals the cleverly engineered and enhanced dial and movement with its myriad materials and finishes. We dive deep into Greubel Forsey’s universe of excellence.

The mechanism reveals itself in its countless details, characteristic Greubel Forsey lines and very high levels of hand finishing performed on each and every component and surface. This pursuit of excellence can be found in even the most unlikely places, including the words central to the Greubel Forsey philosophy, which are engraved around the flanks of the movement itself. Subtle and yet unexpected.

The timepiece is truly brought to life with superior black polishing, satin finishing, circular-graining and superb hand-beveling (with sharp internal angles). The dial side is certainly worthy of attention with its expertly hand-polished blue gold dial to obtain the celebrated flawless black polish that captures the light. The caseback is equally deserving of admiration with its aesthetically balanced openings perfectly integrated into the mainplate.

These apertures highlight the differential bridge – which has been openworked and integrated into the form of the mainplate – underlining the two regulating organs, which also feature extensive hand-beveling and black-polished finishes.

This particularly harmonious creation is complemented by two distinctive gold plates engraved with the words “Greubel Forsey” and the individual number of each timepiece, and the setting of olive-domed jewels in polished gold chatons. The timepiece’s transparency is further enhanced by anti-reflective coatings on both sides of the crystals.

Every part of the timepiece has been lavished with uncompromising attention to detail. Even the crown is made from sapphire crystal and engraved with the distinctive “GF” mark. It has been carefully developed to ensure user comfort during winding, with its every detail being minutely analyzed, from its diameter and thickness to the shape and number of its notches.

The polished white gold hands make it easy to read the time by day and by night thanks to the tips filled with Super-LumiNova. At 2 o’clock, the dial’s 72-hour chronometric power reserve displays the remaining autonomy provided by the movement’s two barrels. Last but not least, the case’s distinctive design is punctuated by Greubel Forsey’s eight unique and original screws, which feature a characteristic notch shape and provide additional water-resistance (3atm, equal to 30 m or 100 ft).

Technical Characteristics: The hand-wound movement incorporates 284 components, 30 of which comprise the Constant Spherical Differential. 71 components make up each of the two escapement platforms inclined at 30° angles. Power is supplied by two series-coupled fast-rotating barrels, which provide the timepiece with optimum force throughout its 72-hour chronometric power reserve. The two oscillators have variable-inertia balances with gold mean-time screws and beat at 3Hz or 21,600 vibrations per hour. The nickel silver plates and bridges are frosted and spotted, with polished beveling and countersinks, straight-grained flanks and an anthracite grey PVD treatment.

The sapphire crystal case – featuring three-dimensional, variable geometry-shaped lugs – measures 47.25 mm in diameter and 13.81 mm in height. The caseback, bezel and case body are each entirely machined from a single piece of sapphire crystal.

The timepiece is complemented by a blue rubber strap, elegantly ribbed and inscribed with the exclusive Greubel Forsey signature on the upper surface, while on the inside in relief are the words pivotal to the Atelier’s philosophy. The strap is completed with a Greubel Forsey engraved folding clasp in titanium.

All the inventiveness and artistry of Robert Greubel and Stephen Forsey are revealed in this magnificent creation.

This Double Balancier Sapphire with mirror polished blue dial is issued as a Limited edition of just 11 pieces, built by the expert hands of the Greubel Forsey Atelier, exclusively for our North American partners. Available at Cellini Jewelers.