The Audemars Piguet 20th Century Complicated Wristwatches book, records that prior to 1986, tourbillon timepieces were a rarity for the Le Brassus based watchmaker. How rare? Audemars Piguet’s archives have revealed that there are only four mentions of the pocket watches made by the watchmaker that had tourbillon escapement.

At the tail end of the Quartz Crisis, however, Audemars Piguet recognized that “business as usual” was not going to work if the Swiss Watch industry wanted any sort of edge ahead of the Japanese whose electronic watches had taken the world by storm. It is with this in mind that the watchmaker launched one of its most audacious creations in 1977, the 36mm and 7mm thick, ref. 5548 Perpetual Calendar powered by the calibre 2120/2800, designed by the one and only, Jacqueline Dimier. But the 5548 isn’t the only project that Audemars Piguet took on to tackle these dark days.

Before we discuss chapter two of this story, first an extract from an earlier article published on Revolution.Watch, about two gentlemen: movement constructor Maurice Grimm and project manager André Beyner of Ebauches SA.

How the World Got Its First Automatic Tourbillon Wristwatch

While companies were collapsing in the Jura, in Neuchâtel two engineers had a vision of how the industry could marry the skills of Swiss watchmakers with quartz technology. Remember, this was the end of the 1970s and most of the great Swiss watchmakers had been making slim, elegant watches for a few years and these were at the opposite end of the timekeeping spectrum to the average quartz watch. The two watchmakers – movement constructor Maurice Grimm and project manager André Beyner of Ebauches SA – had an idea for a quartz watch which would not only be thin and elegant, but one which would change the way watches were made.

Any watch comprises four distinct components: a power source; a regulating mechanism, which turns that power into units of time; a transmission system connecting the regulator; and the final component, the display. The brilliant idea of the Neuchâtel team was to split the components horizontally rather than stacking them vertically on top of one another.

The new watch design was rectangular, and the case was split into three areas – a central dial area and two smaller areas, one above and one below the dial – by placing a tiny battery in one area and the electronics in the other meaning that the overall depth was governed only by the height of the centre pinion and the single wheel below it.

The reduced height was further aided by the decision to abandon the centuries-old convention of plates and bridges. The case was machined from a solid piece of gold, resulting in a shape like the lid of a shoe box, the components were fitted into their respective areas, then the dial and hands and finally a thin sheet of sapphire glass was fitted to close the watch.

At 1.98mm thin, the (aptly named) Delirium was the slimmest watch in the world and sold well, but the truth was that the small market for high-end quartz watches was not going to save the Swiss watch industry and, as if to emphasise that fact, Beyner and Grimm both left Ebauches SA. But with time on their hands, they looked around and noticed that two companies in Switzerland were now getting into the EDM business and this gave them an idea. They went back to work, and over the next few months, worked this idea into a patentable form, filing Swiss patent 007961/1980 on 24 October 1980; their design for an ultra-slim, self-winding wristwatch.

By using the same idea as in the Delirium (that of rearranging the normal components in an unconventional way they were able to drastically reduce the height of the watch. While dispensing with plates and bridges is possible in an electronic watch, it had never been tried in a mechanical one. The breakthrough was to use the case as the mainplate of the movement with a single large bridge as the other support for the pinions. The other eureka moment came with the realization that a winding rotor does not necessarily have to go through 360 degrees, as long as it can move the winding wheel one click at a time.

With this prototype, Beyner and Grimm succeeded in pushing watchmaking’s boundaries, producing the world’s first automatic-winding, ultra-thin tourbillon. At only 2.7mm thick they established a record by integrating the movement with the case back (Picture courtesy of Phillips)

They used a very heavy pendulum with a limited swing of only about 15 degrees, the height of the movement was kept as low as possible by sinking the majority of the pendulum’s weight into the case-back and the efficiency increased by using two of the heaviest and densest metals known – platinum and iridium. The case/movement combination only became possible because of the new electronic erosion machines, which were able to produce such precisely finished parts. Because the case/movement was one piece, it was not possible to make it on conventional machinery and then hand finish it – it had to come from the machine fully-finished and only the electronic erosion machines could do this.

The patent was assigned to Ebauches SA, which decided that the market for slim gold dress watches had dried up and that there was little point in manufacturing it. They also had the problem of being a company that made movements for other companies to install in cases. That was not a possibility with Grimm’s idea – in essence there was no movement, it could only exist as a complete watch and Ebauches SA had no experience in selling watches so quietly shelved the idea and Beyner and Grimm went back to looking at what was not only possible, but practical.

Three years later, as Electro Discharge Machining (EDM) precision developed further, Beyner and Grimm came up with an intriguing idea; what if they tried to use a machine to make a tourbillon cage? No milling or boring machine was capable of this, but close tolerances and excellent surface finishing were the raison d’être of EDMs. So they gave it a try, and, in just over a year, they had a working tourbillon – and not just any working tourbillion: As a “proof of concept” they had made the world’s smallest tourbillon, only 7.2mm in diameter and weighing just over one tenth of a gram (0.123 grams to be precise).

The dial of the Beyner and Grimm prototype sold by Phillips in May 2016 clearly shows the logo of Ebauches SA or, as it later became known, ETA (Picture courtesy of Phillips)

One of the basic rules of technology is that when you take one untried mechanism and combine it with another untried mechanism, you don’t double your potential problems, you square them. Undeterred, Beyner and Grimm decided to add their new tourbillon cage to the slim automatic rejected by Ebauches SA a few years earlier. After a considerable number of false starts, they got it up and running and built a series of prototypes to prove the viability of the concept.

Normally such prototypes are kept locked away in the manufacturer’s archives, or even destroyed, but in this case Beyner and Grimm’s final prototype appeared at auction as lot 200 in the May 2016 Phillips Geneva Watch Auction: THREE, complete with much of the documentation. The watch fetched CHF 30,000.

But while Beyner and Grimm knew the watch could be made in quantity if needed, they realised that there were two vital questions. Firstly, who would make it – none of the Swiss watch companies had yet made the investment in the new machinery. Secondly, was there actually a market for a tourbillon wristwatch – not only had one never been sold commercially, but fewer than 20 wristwatch tourbillions had ever been made, so this was probably the very definition of an untried market.

The first hurdle to be crossed was choosing a manufacturer. It could only really be one of the three grande maisons – Patek Philippe, Vacheron Constantin or Audemars Piguet. Patek Philippe was ruled out as too conservative and of the remaining two, Audemars Piguet was the obvious choice as the new watch was very slim and was known for ultra-slim movements, the “9 douzième” holding the record as the world’s thinnest movement for many years. In addition, Audemars Piguet was still run by the founding family and so the decision path was very short.


The centrepiece of the watch’s dial is the tourbillon aperture – a familiar sight today, but a rarity in the 1980s. The tourbillon represents the sun with the rays crossing the dial from this point. Inspired by Egyptian carvings, the watch became known as “Ra” – the sun god

The advantages to Audemars Piguet were many. It didn’t need a huge investment, as the case/movement and tourbillon components could be produced by the prototyping company who had done the work for Beyner and Grimm, while the assembly would be done by their underemployed master watchmakers. But the key advantage was that it would put Audemars Piguet back on the top of the tree once again – the first company to make a self-winding tourbillon as part of its regular production. And, at the Basel Fair in 1986, Audemars Piguet launched the Ra Tourbillon Automatique, initially in yellow gold and later in platinum.

It is interesting to look at the differences and similarities between the production watch and lot 200. The major difference is that the production watch is turned through 180 degrees compared to the prototype, the production version has the tourbillon at the top and the pendulum at the bottom, which is not only aesthetically pleasing but gives prominence to the tourbillon, which (after all) was its key feature. Obviously, the watch does not bear the name Audemars Piguet – in fact there is no name on it at all, instead where a brand name should be on the finely guillochéd dial, is an applied shield. The observant viewer will recognize the Ebauches SA logo – Beyner and Grimm’s previous employer, now known as ETA.

Diagram showing the pivot of the oscillating mass for the automatic winding system, courtesy of Audemars Piguet Archives
The tourbillon mechanism of the of the Calibre 2870 which weighed but a mere 0.123 grams)

The Royal Oak Tourbillons Through Time

At this time, the man at the helm of Audemars Piguet was none other than Georges Golay. Under his care the watchmaker had already launched two legends in the making: the 1972 Royal Oak ref. 5402 and the later 5548 Perpetual Calendar. This was against this backdrop to which Beyner and Grimm had brought Audemars Piguet their self-winding tourbillon prototype.

Golay in turn, took the knowhow and handed it to a particular Serge Meylan, a young movement constructor who had recently joined workshops. His task was to take Beyner and Grimm’s prototype and create a watch that that the watchmaker could call its own.

Young Meylan took on the challenge and possibly one of the world’s smallest tourbillons (7.2mm diameter) and gave it a titanium cage for stability and lightness. The use of titanium here was another first in the world of watchmaking.


Selfwinding tourbillon prototype. 18-carat yellow gold. Prototype made circa 1985. Audemars Piguet Heritage Collection, Inv. 538.

To give the watch a face, Golay turned, yet again, to the lady who gave the 5548 its dial: Jacqueline Dimier. The Audemars Piguet 20th Century Complicated Wristwatches book records, “…Jacqueline Dimier drew inspiration from an astronomical metaphor. The tourbillon placed at 11 o’clock represented the sun whose rays adorned the elliptical dial punctuated by 12 circular hour-markers like as many planets. A half-moon-shaped aperture at 6 o’clock revealed the self-winding rotor, whose oscillation was reminiscent of the wide balance wheels of historical clocks. To ensure a pure, uncluttered design, the time-setting crown was concealed under the case.”

Between 1986 and 1999, the Model 25643 powered by the calibre 2870 as it was named, Audemars Piguet delivered approximately 401 of these watches. The Audemars Piguet 20th Century Complicated Wristwatches book records further, “In the same way as the perpetual calendar in 1978, the tourbillon introduced in 1986 forged a new path for the entire high-end watchmaking sector, which renewed ties with this escapement specialty, interpreting it in countless different ways. At Audemars Piguet, several generations of tourbillons succeeded calibre 2870, displaying ever greater robustness and reliability, produced since the 1990s in workshops in Le Locle under the supervision of Giulio Papi, and often combined with other complications such as the chronograph, the calendar or the repeater.”


Selfwinding tourbillon. 18-carat yellow gold case No 296. Calibre 2870. Model 25643BA with lug bar cover. Watch sold in 1990. Audemars Piguet Heritage Collection, Inv. 1057.

On the occasion of the Royal Oak’s 25th anniversary (1997), Audemars Piguet gave the family of watches its first tourbillon piece, the ref. 25831ST, powered by the automatic caliber 2875. The watch was made in a limited edition of 25 pieces and was at that time world’s most expensive steel watch. On top of the steel version, pink gold, platinum and yellow gold as well as a one-of-a-kind model combining pink and white gold versions were made limited to 5 pieces each.


Royal Oak Tourbillon. Selfwinding, date, 52- hour power-reserve indication. Movement No 386194, 18-carat pink gold case No D99406, 01. Calibre 2875. Model 25831OR issued in a fivepiece limited edition. Audemars Piguet Heritage Collection, Inv. 910.

Again, on the occasion of the Royal Oak’s 40th anniversary (2012), Audemars Piguet gave us the ref. 26510OR in a 41mm 18-carat pink gold case powered by the hand-wound calibre 2924. The same year, also, saw the incredible 40-piece limited edition ref. 26511PT, a 41mm platinum piece powered by an openworked take on the hand wound calibre 2924.


2012: The Audemars Piguet Openworked Extra-Thin Royal Oak Tourbillon 40th Anniversary Limited Edition, in a 41mm 950 platinum case powered by the hand-wound Manufacture Calibre 2924; issued in a limited run of 40 pieces


2012: Celebrating the Royal Oak's 40th Anniversary, Audemars Piguet introduced the Royal Oak Extra-Thin Royal Oak Tourbillon, with a 41mm 18-carat pink gold case powered by the Hand-wound Manufacture Calibre 2924

The next landmark year for Audemars Piguet where the tourbillon is concerned was 2018. At SIHH that year, Audemars Piguet unveiled their first flying tourbillon timepiece (hand-wound calibre 2954), with the Royal Oak Concept Flying Tourbillon GMT, as well as the bejeweled Royal Oak Concept Flying Tourbillon (hand-wound calibre 2951). The year also saw a refresh to the Royal Oak Tourbillon Extra-Thin ref. 26522, powered by the hand-wound calibre 2924.


in 2018, Audemars Piguet introduced their first use of the flying tourbillon mechanism with the Royal Oak Concept Flying Tourbillon GMT


The 2018 Royal Oak Tourbillon Extra-Thin with the new Tapisserie Evolutive pattern in the Plum Tone dial. (© Revolution)
Caseback of the 2018 Royal Oak Tourbillon Extra-Thin with the new Tapisserie Evolutive dial (© Revolution)

Audemars Piguet brought with the ref. 26522 a brand-new take on the Royal Oak’s signature tapisserie dial with and introduced the “Tapisserie Evolutive” pattern. The press material from SIHH 2018 described the new dial pattern as, “a splendid sunburst pattern.” Immediately, the mind is drawn back to the design that Jacqueline Dimier had given Audemars Piguet’s first automatic tourbillon back in 1986, the Model 25643.

A closer look at the 2018 Royal Oak Tourbillon Extra-Thin's Tapisserie Evolutive dial. (© Revolution)

Now, in 2020, just before the year closes, Audemars Piguet has announced the Royal Oak Selfwinding Flying Tourbillon ref. 26530. In fact, the Royal Oak’s first automatic flying tourbillon. The movement used to power the watch is the self-winding calibre 2950, which first made its appearance in the Code 11.59 in 2019.


Royal Oak Selfwinding Flying Tourbillon // 41 mm ref. 26530ST.OO.1220ST.01, featuring a smoked blue dial with “Evolutive Tapisserie” pattern, powered by the selfwinding Manufacture Calibre 2950


Royal Oak Selfwinding Flying Tourbillon // 41 mm ref. 26530OR.OO.1220OR.01 featuring a smoked grey dial with “Evolutive Tapisserie” pattern, powered by the selfwinding Manufacture Calibre 2950

The Royal Oak Selfwinding Flying Tourbillon ref. 26530 is being introduced in three variations. The first is a stainless-steel version with a smoked blue dial with the “Evolutive Tapisserie” pattern, one in 18-carat pink gold with a smoked grey dial with the “Evolutive Tapisserie” pattern. The piece is possibly the most interesting, in titanium with a sandblasted slate grey dial with snailing on the periphery.


Royal Oak Selfwinding Flying Tourbillon // 41 mm ref. 26530TI.OO.1220TI.01, featuring a sandblasted slate grey dial with snailing in periphery, powered by the selfwinding Manufacture Calibre 2950

Material and dial differences aside, and aside from the movement, the one cool thing to point out on the new timepieces is the applied Audemars Piguet logo on the dial. According to the watchmaker, the gold logo is galvanically grown, much like 3D printing. The individual letters are connected by indecipherable links and then secured to the dial by means of feet that fit into slots. The technique was first used on the smooth lacquered dials of the Code 11.59 by Audemars Piguet.

Technical Specifications


Selfwinding Manufacture Calibre 2950; hours and minutes; flying tourbillon; 65-hour power reserve


Diameter: 41mm; thickness: 10.4mm; stainless steel, titanium or 18K pink gold; water resistant to 50m


Metal bracelet matching case with AP triple-blade folding clasp


Stainless steel: CHF 129,000
Titanium: CHF 129,000
18K pink gold: CHF 159,000