The Pièce de Résistance of the Double Balancier Concept

The Pièce de Résistance of the Double Balancier Concept

The saying “Good things come to those who wait” rings especially true with Greubel Forsey’s (GF) latest creation, the Double Balancier Convexe, that took a decade and a half to get here. The Double Balancier (DB) concept was first patented in 2007 and subsequently exhibited in a single prototype from GF’s Experimental Watch Technology (EWT) department, as first discovered by our friends at Hodinkee. That prototype had both balances and escapements stacked one on top the other between seven and nine o’clock, and inclined at a gentle 20° angle. There were three subdials for the running seconds — one for each regulating organ and a larger third subdial placed in the middle that showed the average of its two smaller siblings.

Then came the first Double Balancier produced in series in 2013, albeit in a small run of only six pieces. Both balances were separated for the first time at five and nine o’clock, conjoined only by a spherical differential hidden away beneath the single running seconds subdial at seven o’clock. They were positioned at a more extreme 35° of lean in different three-dimensional planes. This was probably the first time anyone saw that a standard balance with a lever escapement could look (and function) this extreme. The 72-hour power reserve indicator at two o’clock also made its debut in this watch. So proud were GF of this achievement that they had a short heartfelt message engraved on the side of the caseband: (translated from French) “We, watchmaking inventors, have given life to this exceptional timepiece, a subtle alchemy between creativity and technicality. Our exclusive know-how and craftsmanship are reflected in the complexity of this achievement developed for you.”

The 2013 Double Balancier (image: Time and Watches)
From Greubel Forsey to you. (image: Time and Watches)

In 2016, having acquired two patents for its invention, GF would reformat the DB’s dial layout by pulling back the curtain of the dial further and revealing the sublime, multi-tiered constant differential that is at the heart of the concept. This time, the seconds subdial would play second fiddle to the differential and unfortunately be relegated to a less prominent location on the dial. Apart from minor design tweaks to the power reserve indicator and dial color and font, the aforementioned changes were the most prominent and arresting. By revealing the inner workings of the movement, the wearer is treated to more of the spectacle of the mind-bending depth of construction, with the dual balances angled at 30° this time. The delight of experiencing the magic of the invention surely remained long after the trick was revealed.

A sketch of the inclined double balance concept with central differential (image: Greubel Forsey)
Greubel Forsey Double Balancier
There's much more to see on the 2016 Double Balancier (image: Greubel Forsey)

2022’s Double Balancier Convexe distills the past 15 years of Greubel Forsey’s savoir faire into a single watch, not only incorporating design cues from the last two DBs, but, crucially, using the titanium ovoid case (now in 43.5mm) first seen in the 2019 GMT Sport — a clear departure from the traditional round, white gold case that was used in previous DBs. Its shape is neither oval nor tonneau, but a perfect blend of the two. To accommodate this unique shape, the movement and the sapphire crystal, front and back, had to be fashioned to follow the same contours. No cheating going on here by using a flat caseback. The lugs are in profile to the case, and the provided rubber strap with titanium folding clasp is screwed directly onto them. From the front, it looks as if there are no lugs at all. Therein lies the genius of the seemingly lugless design. The rubber strap can be swapped out for a three-link titanium bracelet, which when attached, flows seamlessly into the case. Bam! Instant transformation into an “integrated” bracelet watch. Disappointingly, the titanium bracelet with fine adjustment in the clasp is not included, but can be requested for separately.

Greubel Forsey Double Balancier Convexe
A lugless case accommodates both a rubber strap or metal bracelet seamlessly (image: Greubel Forsey)
Greubel Forsey Double Balancier Convexe
You can barely tell where the case ends and the bracelet begins (image: Greubel Forsey)

On the face, gone are the proud inscriptions on the bezel of the Balancier S and the DB Convexe simply lets its art and engineering do the talking instead. The bezel itself sits a few millimeters proud over the caseband, accentuating the view of the dial. And what a dial this is.

More than half the dial has now been opened in what can only be described as an asymmetric semicircle with the engraved and lacquered 72-hour power reserve indicator at two o’clock the only holdout left standing on it. The double barrels stacked co-axially (on the same axis) at 10 o’clock now push out from under the dial by way of an inscribed barrel cover. Interestingly, the barrels move at a pace more than twice as fast as a conventional barrel would, one revolution in 3.2 hours compared to eight. And despite the movement being manually wound, one of the mainsprings has a slipping bridle (only seen in automatic movements) to relieve excess tension build-up as they are being wound.

At the periphery, the minute track is also engraved and lacquered with Super-LumiNova filled, applied indices at every five-minute interval. The minute and hour hands are filled with Super-LumiNova as well and curved to accommodate the curvature of the dial and crystal. The motion work that drives these hands are now supported by an open-worked mini bridge that rises from the movement plate to meet them on the elevated plane.

To give the balances and constant differential space to do their thing, the top barrel directly drives the cannon pinion, doing away with the need for a traditional wheel train layout. It is unclear whether there is a wheel train connecting the fourth wheels of the respective balances to the running seconds indicator as we aren’t privy to what’s underneath it. However, it stands to reason that the running seconds should be an average of the oscillating output of both balances.

Greubel Forsey Double Balancier Convexe
The Double Balancier Convexe employs a more compact wheel train layout (image: Greubel Forsey)
Greubel Forsey Double Balancier Convexe
An inclined gear on the fourth wheel is the link between the horizontal plane and the inclined plane (image: Greubel Forsey)

If you’re wondering how the Double Balancier concept pursues chronometry, well, for one it’s not like the other, more common type of dual-balance watch, which relies on the resonance or vibration effect to improve accuracy. The inclined balances, currently leaning at 30° within the escapement platform, are never in an absolute perpendicular orientation when the watch is in the vertical positions. Therefore, the full downward pull of gravity is never experienced by the balances. The use of a Breguet overcoil (also known as a Phillips terminal curve because mathematician Edouard Phillips improved on Breguet’s design) also positions the center of gravity of the oscillation toward the center of the balance staff. Aesthetically, we like that the balances use timing screws instead of timing weights, as a nod to tradition and a counterpoint to a mostly contemporary design.

The differential between the balances employs a constant force mechanism to regulate the speed of each balance, thereby averaging out the speed of their oscillations, bringing them in sync with one another. There are what amounts to three third wheels arranged in a column in the differential, with the top and bottom wheels driving the two individual fourth wheels on the right and left of it. There is a spiral spring, pinned at two of the three spokes of each wheel, that acts as a tensioner, releasing and receiving energy from the balance in a controlled manner. The wheel in the middle of this stack turns with the force that has been equalized and drives the center wheel, and then the rest of the motion work. The fourth wheels themselves use an inclined gear to drive the inclined escape wheels. That’s how the wheel train transitions from a horizontal to an inclined plane.

A polished blued steel hand sits atop the whole contraption and indicates the number of minutes it takes the differential to make one revolution. Why four minutes you ask? Well, the gear ratios in the differential have to be doubled to receive the energy from two balances, and if one balance were to stop moving, it would take the seconds hand two minutes instead of one to make one revolution.

Greubel Forsey Double Balancier Convexe

All that scientific engineering is made beautiful by the art of the movement’s finishing. Here we find the bridges with polished bevels, countersinks for the screws, and straight-grained flanks just for variety. The flat top sides of the differential and balance bridges are also flat black polished. Black frosted treatment of the dial and mainplate lets all that bright work not get lost in the view. With so much to see, the overall design has visual harmony in its high level of finish and color contrast despite the intentional asymmetry of the dial layout. Pablo Picasso said it best and it very much applies here: “Learn the rules like a pro, so you can break them like an artist.”


Robert Greubel and Stephen Forsey first made a name for themselves by reinterpreting how a tourbillon should be presented on a dial (i.e. at an angle). Over the years since 2004, they have continued to outdo themselves by adding more of a good thing (up to four tourbillons) to their watches, and then came the “flying” globes of their equally extreme GMT watches. GF watches were always packed to the brim with horological sculptural architecture, but rarely caught the attention of the mainstream enthusiast as they often seemed too heavy and unwearable. All that changed when Antonio Calce took over the reins from the founders in 2021 and realigned the brand’s focus of creating everyday wearable watches but keeping the architectural forms that made them famous. And it shows. The Double Balancier Convexe ticks every box of that brief, and then some.

Its appeal lies in the fact that it is a watch that goes about its simple function in a most complex and artful way. Yet, its complexity has a purpose in the pursuit of chronometry and does not get in the way of its usability. The titanium ovoid case, which is surprisingly water-resistant to 100m, compensates in weight savings what certainly would have been a lumbering beast of burden on the wrist, had it had been sculpted from precious metal. The endless curves feel natural against your skin, with titanium being hypoallergenic and impervious to rust for all intents and purposes. Whether you choose the rubber strap or titanium bracelet, you could dive with it, work out with it, and then go chill at the bar with it — and its inclined balances and constant differential wouldn’t skip a beat either way. You might also experience the added benefit of going incognito, as it is highly unlikely anyone else would know what you have on your wrist — or have the same watch on theirs, for that matter. The power reserve of 72 hours is plenty to tide you over the weekend, in the unlikely event you take this beauty off from daily wear.

While the price of the DB Convexe has yet to be confirmed, it would most likely be in the ballpark between the price of its cousins — the Balancier S at CHF 195,000, Balancier S² at CHF 205,000, and the last white gold 2016 Double Balancier at CHF 350,000. A lot of money, for sure, but each one truly limited and special.

There has been much debate on the secondary market values of stainless steel sports watches that every mother’s son (and daughter) seems to want. Is an end-of-series green dial or Tiffany blue dial really worth hundreds of thousands, or even millions of dollars? Does a 15202 or 16202 really look all that different from a 5402? Some say these companies are undercharging for their icons, and the retail price does not reflect what the market is willing to bear. This is life imitating art, imitating life, and so it goes on. Will we ever see the end of this fever pitch in demand for the same watches, and every other company offering an alternative to try and capture market share?

If you have that kind of cash to drop, it’s time to look elsewhere. To watches and watchmakers that are attempting something new. Not just a rehash of what’s been done before. Nostalgia will always have its place — we are human, after all — but maybe it’s time to look ahead. Where Greubel Forsey goes next is anyone’s guess, but the Double Balancier Convexe and its future progeny could very well be the next big thing in luxury sports watches. And they would be worth every penny.

Greubel Forsey Double Balancier Convexe

Tech Specs

Greubel Forsey Double Balancier Convexe

Movement: Manual-winding with two patents; 72-hour power reserve
Functions: (all patent pending): Double Balancier, hours, minutes, small seconds, four-minute spherical constant differential rotation, power reserve
Case: 46.5mm x 14.35mm (including bezel width and curved sapphire crystal height); 43.5mm x 13.75mm (case alone); titanium; water resistant to 100m
Dial: Black asymmetric semicircle with engraved, lacquered power reserve indicator; three-dimensional, variable geometry hour-ring with engraved, lacquered minute track; Super-LumiNova filled applied five-minute indices
Strap: Rubber with texture in relief; titanium folding clasp with engraved GF logo. Three-link titanium bracelet with fine adjustment folding clasp available on request.
Price: TBC
Availability: Limited edition of 66 pieces total, made from 2022–2024; 22 pieces per year.