New: Greubel Forsey Double Balancier Convexe S2

Greubel Forsey extends its collection by combining themes into one. Presenting the new Double Balancier Convexe S2. The complication of the Double Balancier in a sporty case.

Press Release information with commentary in italics.

Greubel Forsey Double Balancier Convexe

The retail price without taxes is:

• CHF 295,000 for the Double Balancier Convexe on the ballistic strap,
• CHF 335,000 for the Double Balancier Convexe on the titanium bracelet.

Commentary

The meeting of two complications is an interesting concept. The Double Balancier is a very complicated watch, with two balances inclined at 30°, driven by a single drive train. A spherical differential averages the timing rate of both balances. This is theoretically more complicated than the Dufour Duality, as both balances are now inclined instead of being flat, requiring a spherical differential, instead of a flat one used in the Dufour.

We covered the 2016 Double Balancier à Différentiel Constant in our review. The new watch uses the same movement, we recommend reading the review, as we discuss the technical details of the complicated movement.

In summary, the movement has one mainspring and one drive train which delivers power to both the balances. Each of the balances are completely independent of each other. And each inclined at 30° to the dial surface, which also ensures that they are also inclined to each other. The most common resting position for a watch is either crown up/down or dial up when set on a table top. In these positions, the beat errors are the greatest. By setting the balances at 30°, GF tries to limit the time each balance spends on the horizontal or vertical positions even when the case is horizontal or vertical. And even if one balance is in such a poor performing position, the other will not.

In this new release, Greubel Forsey cases this amazing movement in their new S2 case, which debuted as the Balancier S². The S2 is a development over the S case, revealed in 2019 as the GMT Sport. The case remained 46.5mm, measured across the long side, and 43.5mm along the short side of the oval case. The dimensions may seem rather huge, but in reality, the watches wear smaller. This is a complex case shape, with strong curves in all directions, accentuating the organic nature of the design. And wrapping itself around the wrist. As with the Balancier S², the new Double Balancier Convexe S2 is also available with their new titanium bracelet. As is customary with Greubel Forsey, the bracelet is exceptional in design and finishing, though at a rather large ransom of CHF 45,000.

As with all Greubel Forsey, the production is extremely limited, and only 22 Double Balancier Convexe will be made each year between 2022 and 2024, making a total of 66 pieces. We expect the level of finishing on this new watch to be the exceptional top level we have come to expect from Greubel Forsey, and the high resolution photographs we have received seem to agree with this assumption. We have requested for a hands-on and photography session with the novelty, and will report back when we do.

Release information

With every invention, Greubel Forsey has added a significant milestone to the history of watchmaking. The Double Balancier, patented in 2007, is one of them. It was first demonstrated in an EWT (Experimental Watch Technology) prototype, with two superimposed regulating organs inclined at 20°. A second iteration followed soon after, this time in a six piece unique edition with the two regulating organs positioned in different three-dimensional planes and inclined at 35°. Finally, in 2016, Greubel Forsey presented the invention in its current, double-patented form: the two balance wheels are dissociated, inclined at 30° and separated by a constant spherical differential which calculates their average timing rate.

Today, Greubel Forsey unveils a new timepiece emphasizing the architectural dimension of its 6th invention that is the Double Balancier. The three regulating organs (two balance wheels, one differential) occupy more than half of the dial and provide unprecedented depth. The timepiece is contrasting, highly technical and more contemporary than ever.

The timepiece gets its name from the convex profile of its 43.5mm titanium case. It’s plunging lines that hug the curve of the wrist raised significant technical challenges, requiring the sapphire crystal and above all the movement to adopt to this unique shape. This new composition showcases its movement spectacularly. The gear train emerges from below the surface of the seemingly semicircular black-treated titanium bridge and extends into the hour and minute hands which tower above it. The semicircle itself is rendered asymmetrical by an opening for the barrel cover, central hours
and minutes indication, and by an opening which provides space for the small seconds indication below it. The engraved and lacquered minute indexes are nested within the three-dimensional chapter ring, but the polished hour indexes surpass it, plunging deep into the movement.

Each hand has its own geometry, finish and color, depending on the role assigned to it. The hour and minute hands take on a curved profile and are filled with Super-Luminova, complementing that of the hour indexes. The small seconds and 4-minute hand indicating the rotational speed of the spherical differential are in polished blued steel while the power reserve is indicated by a polished and openworked hand with a red tip.

In the lower half of the Double Balancier Convexe, each regulating organ is sculpted individually. The two balance wheels, although identical in shape and function, occupy different planes and thus offer a complementary spectacle. The center bridge is in itself a showcase of the creative excellence of Greubel Forsey: multi-level, openworked and black polished with several interior angles, it carries the hour and minute hands above the movement. The inclined escapement platforms are straight-grained with handpolished beveling and countersinks, while the differential bridge and balance wheel bridges are flat black polished with further hand-polished beveling. Every single component is hand finished to Greubel Forsey criteria and thus stands out on its own, and at the same time it contributes to the striking overall æsthetic of this timepiece.

The bridges and mainplate of the Double Balancier Convexe are in frosted and black treated titanium. A new font has been adopted for the power reserve and different elements throughout this timepiece. On the barrel cover, we discover relief-engraved text, circular-grained with polished chamfer, describing the properties of the two coaxial barrels in series with rapid rotation (one revolution in 3.2 hours). They drive a 374-part movement, endowed with a 72-hour chronometric power reserve materialized by an openworked hand.

The integrated and profiled lugs reinforce the compact and ergonomic character of this timepiece. They extend onto either a textured rubber strap or titanium bracelet. Last particularity: the Double Balancier Convexe, like most of the contemporary creations of the Atelier, is now water resistant to 100 meters – a detail that does not mislead on its vocation to be worn daily, in all circumstances. Only 22 Double Balancier Convexe timepieces will be made per year between 2022 and 2024 for a total of 66 pieces overall.

Greubel Forsey Double Balancier Convexe Specifications

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

MOVEMENT
NUMBER OF PARTS
• Movement: 374
NUMBER OF JEWELS
• 50
• Olived-domed jewels in gold chatons
CHRONOMETRIC POWER RESERVE
• 72 hours
FREQUENCY
• 21’600 vibrations/hour
PATENTS PENDING
• Double Balancier
• Hours and minutes
• Small seconds
• 4-minutes spherical constant
differential rotation
• Power-reserve

EXTERIOR
CASE
• Titanium with curved synthetic sapphire crystal
• Three-dimensional, variable geometry-shaped bezel,
hand-polished with hand-finished straight graining
• Raised engraving “Double Balancier” and “Greubel Forsey”
CASE DIMENSIONS
• Diameter: 43,50mm (caseband) and 46,50mm (bezel)
• Height: 13,75mm (case) and 14,35mm (synthetic sapphire crystals)
WATER RESISTANCE OF THE CASE
• Water-resistant 10atm – 100m – 328ft
DIAL SIDE
• Three-dimensional, variable geometry hour-ring with engraved
and lacquered minute-circle, black treatment
• Power-reserve indicator, engraved and lacquered
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