Flying Tourbillon – Il Giornale degli Orologi

On 26 June, Breguet unveiled the latest addition to its Classique collection: the Classique Tourbillon Sidéral 7255. This was no ordinary date, but the 224th anniversary of the patent for the ‘tourbillon regulator’. This was filed by Abraham-Louis Breguet on 26 June 1801 — or, rather, on the 7th Messidor of Year IX according to the then-in-force French Republican calendar. And not just any watch: it is the fourth timepiece launched by the Maison to celebrate its 250th anniversary, following the Type XX Chronograph 2075, the Tradition Seconde Rétrograde 7035, and the Classique Souscription (listed here in reverse order from most recent to oldest).

So here comes the long-awaited tourbillon – the one everyone was expecting and speculating about. Although it likely won’t be the only one in this year of celebrations.

But, beyond predictions for the future, the new Classique Tourbillon Sidéral is remarkable in the way it has been developed. In my opinion, it is not only beyond expectations, but also different from any other tourbillon produced so far by Breguet. I would describe it as striking, without any negative connotations. After all, it is a flying, mysterious and sidereal tourbillon. Let us try to understand what that means.

The tourbillon…

Everyone knows what a tourbillon is, but it’s always worth reminding ourselves what it actually is. Essentially, it is a mechanism designed to counteract errors and spatial variations in watch operation. The balance wheel‘s regularity is compromised by negative influences exerted by the force of gravity. This is particularly the case with pocket watches, which are usually kept in a vertical position. The problem lies in fine-tuning and perfectly balancing the tourbillon, which increases manufacturing costs.

The tourbillon, which is inextricably linked to Abraham-Louis Breguet, was invented by him. Its principle consists of mounting the regulating organ (the entire escapement plus the balance wheel/spring system) on a mobile support. This support is technically called a cage and completes a rotation in a given period of time (usually one minute or more). The errors are therefore reproduced cyclically, cancelling each other out with each complete rotation. Tourbillon watches are therefore theoretically more accurate.

…Flying

Our readers should also be familiar with the concept of a flying tourbillon. This is not a device created by Abraham-Louis Breguet, but it is much more recent. It was invented in 1920 by Alfred Helwig, a German watchmaker who taught at the Glashütte watchmaking school. In practice, it is an evolution of the tourbillon, with the cage fixed only at the base on the plate.

Free from the upper bridge, it provides an unobstructed view of its rotary motion, almost seeming to hover in the air — hence the term ‘flying’.

However, this makes the manufacture of the tourbillon even more complex. The manufacturer must address issues of balance and the structure of the cage itself, which must be robust yet light and finely adjustable in any case. Ultimately, it is a display of virtuosity for mere aesthetic purposes.

…mysterious and sidereal

In watchmaking, the term ‘mysterious‘ is used to describe timepieces in which some of the key components remain hidden. The observer cannot understand how power is transmitted to the various parts when looking at it. A famous example is Cartier’s pendulettes mystérieuses, in which the hands appear to be floating in space. In reality, they are attached to a rock crystal disc, which is connected to the movement in the base via a well-hidden vertical axis.

In Breguet’s Classique Tourbillon Sidéral 7255, however, the mystery relates to the tourbillon. Both the tourbillon cage bridge and the base to which it is attached are made of sapphire crystal and are made even more invisible by a surface coating. Since the connection to the time train is lateral to the tourbillon opening and hidden by the dial, the illusion of the tourbillon floating in the void is even more impressive.

The final adjective, ‘sidereal’, which also appears in the name, recalls an astronomical context, as does the splendid aventurine enamel dial, which we will discuss later. As the official literature explains, the reference to the stars also has semantic value. In French, tourbillon means ‘whirlwind’ or ‘vortex’. It was the great philosopher and mathematician Blaise Pascal, who lived between 1623 and 1662, who defined it as a ‘physical structure animated by a revolving motion‘. Hence, by extension, the concept moved on to planetary systems and thus to the entire field of astronomy.

The aesthetics of the Classique Tourbillon Sidéral 7255

Well, after the introductory explanations, I will now proceed to describe the watch. Like the other anniversary pieces, the 38 mm Classique Tourbillon Sidéral 7255 has a case made of Breguet gold. This is an alloy composed of 75% gold, with the remaining 25% consisting of silver, copper and palladium. Warmer than yellow gold, yet more delicate in colour than red gold, its hue is inspired by the gold alloy used during the time of Abraham-Louis Breguet. It is thus a further tribute to the era of the Maison’s establishment.

The observer is immediately struck by the beauty of the dial, which is a fragment of the night sky rendered using the traditional Grand Feu enamel technique. Although it resembles a thin slab of aventurine stone (a type of quartz containing mica inclusions), it is actually a disc made of Breguet gold coated with glass. According to legend, the name ‘aventurine’ comes from the fortuitous circumstances of its invention. It is said that, in 17th-century Venice, a Murano glassmaker accidentally dropped copper filings into the molten glass. The result was a type of glass resembling the starry night sky.

The aventurine enamel dial

In the dial of the Classique Tradition Sidéral 7255, aventurine glass is used instead of enamel in a lengthy and intricate handcrafted process comprising several steps. First, the glass is ground into a powder containing larger grains than usual. Next, the powder is mixed with water to form a paste, which is then applied by hand to the metal substrate using a small brush.

The dial then undergoes a first passage in an oven at a temperature of over 800°C. This process is repeated up to five times until the desired colour intensity is achieved. Unfortunately, there are risks involved in each round, because firing the enamel is very critical and the final result cannot be taken for granted. If something goes wrong, the whole process has to be started again, as the dial has to be thrown away.

The 187M1 Calibre

Turning to the mechanics, the Classique Tradition Sidéral 7255 features a movement inspired by the Classique 3350, the first tourbillon wristwatch created by Breguet in 1988.

It has the same manual winding and ‘full bridge’ architecture, as well as the same hand-crafted decoration. However, the new Calibre 187M1, which can be seen through the large sapphire crystal porthole on the caseback, features different guillochage. This is the custom-made Quai de l’Horloge motif created for the anniversary. Notice the tourbillon aperture on the back: the sapphire crystal surrounding the guilloché gold base makes the device look as if it is suspended in a vacuum.

The movement design is also worth mentioning, as it is entirely focused on the tourbillon, which is further emphasised by its raised position. In fact, the tourbillon protrudes 2.2 mm from the plate and 0.9 mm from the dial. The tourbillon’s thickness reaches 7 mm, defining the volume of the entire movement and case, which is 10.2 mm thick.

The main mechanical specifications can be found in the captions. However, it is worth mentioning at least two pieces of information. Firstly, the balance has a slow and constant frequency of 18,000 vibrations per hour, reminiscent of pocket watches of yesteryear. Secondly, the Nivachron™ balance spring is patented, antimagnetic and blued to make it stand out more inside the balance.

Classique Tourbillon Sidéral: final considerations

There is much more that could be said about the Classique Tourbillon Sidéral 7255, but I will stop here. The complexity of the movement and the challenges involved in manufacturing the dial mean that the Maison can only produce a limited number of pieces: just 50 for worldwide distribution. The exclusivity is also reflected in the price: 225,900 euros.

This is one of those watches that really must be seen in person to be fully appreciated: to admire, touch and wear it is the only way to understand what haute horlogerie is all about. This limited edition means that, in the near future, each of the company’s boutiques globally will receive only a few pieces. However, Italians interested in buying the watch can contact the boutique at Via Montenapoleone 19 in Milan. The rest of us can only visit the official website. And gnaw…

If the great 17th century French philosopher and writer François de La Rochefoucauld were alive today, he might well be wearing a Richard Mille watch. Perhaps the RM 75-01 Flying Tourbillon Sapphire, the brand’s latest model. After all, as he wrote in one of his most famous aphorisms, ‘The only thing that should surprise us is that there are still some things that can surprise us’. This is precisely how I felt when I saw the initial images of this new watch − unfortunately, only those for now. I was astonished.

Above all, I was astonished by the brand’s ability to continually master the most advanced materials in watch manufacturing: Quartz TPT, carbon TPT, ceramic, gold, titanium and, of course, sapphire. Richard Mille’s ability to shape these materials, ranging from ‘simple’ to composite, establishes the brand as one of the most advanced in this field. The RM 75-01 Flying Tourbillon Sapphire is further proof of this, particularly for those familiar with working with sapphire.

Lords of Sapphire

Essentially, it involves operating on the edge of masochism. The sapphire used for watch cases, like the RM 75-01 Flying Tourbillon Sapphire, is a synthetic material produced in a laboratory. Technically, it is synthetic corundum, which is notable not so much for its transparency as for its hardness, which is surpassed only by that of a diamond.

This article explains the process of machining such a hard and resistant material. Over 10 years ago, Richard Mille became the first brand to use this material for watch cases. That was in 2012, which feels like a geological era ago. Consider what has happened to the watch market in the meantime, from the pandemic to the explosion and subsequent implosion in China − just two key episodes.

The RM 75-01 Flying Tourbillon Sapphire continues this legacy and takes excellence even further. The 2012 watch combined two of the most highly regarded complications: a split-seconds chronograph and a tourbillon. This model “limits” itself to a flying tourbillon. However, materials science and calibre technology have evolved at an incredible speed in the intervening 13 years. Richard Mille has kept pace, needless to say.

The colours of the RM 75-01 Flying Tourbillon Sapphire

With that in mind, let me introduce today’s watch. There are actually three versions, as the brand has worked with three different colours of sapphire. More specifically, the sapphire back is available in three versions: completely transparent, blue and lilac-pink. There are several possible reasons for limiting the colour to the case back.

Undoubtedly, creating a fully coloured sapphire case is complex. Minerals must be added to the basic corundum to give the material the desired colour: titanium and iron for blue, for example. Needless to say, achieving the desired shade by finding the right proportion of additives is not easy. Richard Mille certainly does not compromise on quality. However, if a ‘cheap’ solution can be found in terms of cost and processing time, why not use it?

Another possible reason is ‘scenographic’: an entirely coloured sapphire case could distract from the calibre, the real protagonist of the watch’s design. However, more prosaically, I believe that the choice of a coloured case back was made because, despite being only part of the watch and located at the rear, its transparency captures nuances and virtually colours it as well.

This would be an intelligent way to achieve a high-quality result while reducing the effort involved in the challenging production of coloured sapphire. It is no coincidence that only 15 pieces of the fully transparent version are manufactured, while the blue and lilac pink versions are limited to 10 due to obvious production difficulties.

The RM75-01 calibre finish

I will now move on to the movement. This is the hand-wound RM75-01 calibre, featuring a flying tourbillon and an hour and minute display. There are no additional complications, counters or function selectors. It would appear minimalist were it not a Richard Mille. While I will leave most of the technical details to the captions, it is worth emphasising here that the movement is distinguished not only by its mechanical complexity, but also by its very high level of refinement.

The chamfers, locking elements and contact surfaces are hand-polished, as are the pivots. To achieve the micro-peened effect of the milling, Richard Mille used sapphire microspheres. The steel parts have also been sandblasted using sapphire microspheres (the mainplate and bridges are made of titanium) and have polished sides.

As with all the brand’s movements, great care was taken when manufacturing the geared wheels of the RM75-01 calibre. Their concave bevels were made using custom-made diamond tools to achieve micron-level precision. The faces of the wheels have a circular satin finish and are rhodium-plated before the gearing is made, to eliminate any defects or imperfections. The wheels undergo minimal corrections; any alteration to their geometry would compromise the performance of the time train.

Richard Mille DNA

In the press kit for the RM 75-01 Flying Tourbillon Sapphire, the brand describes the watch as “…embodying a metaphysical balance. The modernity and technical sophistication of its sculptural calibre harmonise with a timeless inspiration drawn from historical architecture and the softness of the oceans — a duality that perfectly reflects the brand’s artistic and technical approach, where diverse worlds converge to open new creative horizons“.

I will grant the authors some poetic licence. After all, marketing is neither about technique nor passion. In this sense, the focus on colour nuances inspired by the shades of the sea is fitting. However, we must not forget that this is primarily a mechanical watch, an achievement made all the more impressive by the fact that it combines a complex architectural structure with the basic function of displaying the hours and minutes, enhanced by the flying tourbillon.

Given the commitment to materials, technology, research and development that the Manufacture has invested in the watch, the price tag of around 2 million Swiss francs is entirely predictable. As I mentioned at the beginning, this is something one should no longer be surprised by. Richard Mille embodies innovation, mechanical avant-garde and materials science, as well as an obsession with research. All of this comes at a cost commensurate with the quality of the final product, and the RM 75-01 Flying Tourbillon Sapphire is no exception. Excellence and perfection have never been for everyone.

Tag: Flying Tourbillon

Classique Tourbillon Sidéral and Breguet’s double anniversary