Review: Complications and more complications: Greubel Forsey GMT Quadruple Tourbillon

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Greubel Forsey adds a Quadruple Tourbillon to their popular GMT model, turning it into a complication monster. We get up close to this new beast, and discover its intimate charms.

We covered the details on the Press Release published just before Baselworld 2019. Click here for the details. We also carried live photographs on our Live from Baselworld 2019: Greubel Forsey report. Here is our detailed review with high resolution photographs.

The new Greubel Forsey GMT Quadruple Tourbillon.

Greubel Forsey GMT Quadruple Tourbillon

We covered the Greubel Forsey GMT models in various editions over the course of its history since the inception in 2011 (our coverage is from SIHH 2012). And in a bit of detail in our manufacture tour where among other things, we also featured the GMT in 2014, The Quadruple Tourbillon was first introduced in 2008, and a new version was introduced in SIHH 2011, which we reported here. This new version is used as the base for the GMT Quadruple Tourbillon.

The first version of the GMT Earth (with special inscription on the bezel in micro-writing) taken off the wrist of Stephen Forsey, placed next to the new GMT Quadruple Tourbillon.

This new release is a complication upon a complication: merging the already very complicated quadruple tourbillon to the almost equally complicated GMT. What do we call such a collision of complications? A Mega Complicated Watch?

The case, dial and hands

The starting point is the movement used in the 2011 Quadruple Tourbillon. This in itself was a slight modification to the original quadruple tourbillon introduced as the Invention Piece no2. And the marriage to the GMT which incidentally was also announced in 2011. The case remains the rather large, bulbous one retained from the 2011 Invention Piece.

The case bulges to accommodate the rotating sphere representing the globe at 8. But the case is neither awkward nor in-elegant. This case shape was also adopted in the 2014 GMT. Indeed, it manages to remain composed. Though stealthy it is not. With a design shape which is so unusual, and at a sizable 46.5mm diameter and 17.45mm thick, it is going to have a massive wrist presence.

The case shape is a rather bulbous one with great wrist presence, and a bump at 8 to accommodate the globe. A piece of sapphire glass allows the globe to be observed from the case side.

And the twin double tourbillons are rotated from 1 and 8 in the Invention Piece to 11 and 5 in the 2014 version. The space vacated by one of the double tourbillons in the Invention Piece is taken by the miniature 3 dimensional, rotating ball representing the Earth. Each set of tourbillons comprise of twin axis tourbillon. The inner one is at a 30° angle, 1 rotation per minute, and the outer one makes 1 rotation every 4 minutes. The two double tourbillons are connected via a system of differential conical gearing and are fed power from a single triple barrel mainspring set. Three series-coupled fast-rotating barrels make 1 turn in 3.2 hours and one of which is equipped with a slipping spring to avoid excess tension.

Two Double Tourbillons at 11 and 5, the “main” time dial at 2 with a sector for the power reserve. and the globe with time readout engraved in the periphery. This is a complicated dial. With many levels, and a 3D ball thrown in the mix.

The dial side is very deep, allowing for a three dimensional appearance. A second timezone, or GMT can be read from the 24 hour sub-dial at 4. A global universal time with 24 timezones is engraved on plate surrounding the ball, and local times at each location on the map can be read off it.

The description of the dial side sounds like a recipe for disaster. But in reality, the aesthetics on the dial side is truly spectacular. Some might even describe it as beautiful. The three dimensional aspect of the layout and arrangements in various layers couple with the 3 dimensional ball representing the Earth. A veritable mini-landscape which led us to coin the word “Watchscapes” in Greubel Forsey watches is very apt in this GMT Quadruple Tourbillon.

The movement

The movement is incredibly complex. The movement comprises of 705 parts, with four tourbillon cages. The tourbillons themselves are made up of a total of 260 parts. The spherical differential which distributes power from the single power source to the twin double tourbillons itself comprise of 28 parts. But these components are very small. As an example, the total weight of the cages are a mere 2.25 g.

From the dial side, both the double tourbillons and the Earth ball stand out. From the back, it shows the reverse of the double tourbillons, and a plate showing the 24 timezones and the corresponding city, as a World Time indication. As described earlier, the World Time can also be read via the similar 24 hour scale on the dial side by the corresponding position on the map engraved on the rotating titanium Earth ball.

As usual in Greubel Forsey timepieces, the finishing execution is immaculate and top of the class. Bar none. See our interview with Stephen Forsey where he describes his philosophy on this. Don’t forget to read Part 2 and Part 3 here for the complete picture.

Competitive Landscape

Competitively, there is no other Quadruple Tourbillon in existance that we know of. If you know of one, please let us know in the comments section.

The closest we can think of are multiple tourbillon combined with another complication are either the triple axis versions from various vendors (the Jaeger-LeCoultre Gyrotourbillon in various incarnations comes to mind).

The latest edition on the Jaeger-LeCoultre Gyrotourbillon story. This combines a multi-axis tourbillon with a perpetual calendar and a minute repeater with Westminister chimes.

Perhaps another might be the Jacob & Co Twin Turbo. It features twin triple axis tourbillons coupled to a minute repeater. A second generation of the Jacob was released in 2018 in the form of the Twin Turbo Furious. This adds a chronograph to the mix, making it even more complicated.

Jacob & Co Twin Turbo, on the wrist.

Concluding thoughts

This is Greubel Forsey doing what it does best. Making super complicated watches, with multi tourbillons and nifty practical complications like a second timezone with World Time. Making among the best finished watches in the business. Making watches with great wrist presence, and amazing grail quality. A truly magnificent timepiece.

We guess this is a watch which nobody needs. But will be on the lust list of almost every watch enthusiast who loves an ultra complicated timepiece, or for those who love the supreme finishing levels lavished on it. For us personally, it will remain a dream watch as the price of CHF 780,000 is a great deterrence to our bank accounts. But for those with deep enough pockets, which the Greubel Forsey GMT Quadruple Tourbillon is targeted at, it get a natural and unequivocal “BUY”. And to the naysayers, “Condemnant quo non intellegunt.”



  1. First of all, I like it. But why would this be a Quadruple tourbillon!!? I just see two balances and escapements. So wouldn’t the Jacob be an Hexatourbillon!? Aren’t GF tourbillons just twin axes tourbillons? With one axis inclined?