Montblanc Star Legacy Suspended Exo Tourbillon

Watch internet truism #5789: It’s incredibly easy to be dismissive of a tourbillon.

I think every watch enthusiast, at one point or another, discovers a biography on A-L Breguet somewhere on the World Wide Web, decides they are now a veritable scholar, and has remarked to a friend:

“Don’t you know a tourbillon is only horologically relevant in a pocket watch? What a waste of money!”
I’ll admit, it’s something I may have uttered during my first year or so of learning the watch-writing ropes. But I’ve come to recognize the tourbillon as perhaps watchmaking’s most beguiling anachronism. And to dismiss it with a heavy hand as an oligarch’s personal folly discredits the many mechanically intriguing, intellectually stimulating, and – most importantly – emotionally resonant developments happening in the genre these days.

Take a look at what Greubel Forsey and Roger Dubuis have accomplished in recent years. Or, for even more esoteric examples, Antoine Preziuso and Purnell. Jaeger-LeCoultre has the Gyrotourbillon. MB&F? The appropriately named Thunderdome. And Zenith, the Defy Fusée Tourbillon. Ulysse Nardin, A. Lange & Söhne, F.P. Journe; the list goes on. But your list might not include Montblanc, and that should change. And it’s because of watches like the just-announced Star Legacy Suspended Exo Tourbillon, which is the latest timepiece equipped with the company’s proprietary execution of a one-minute tourbillon. Here’s what you should know.
First revealed in 2010 after three years of research and development, the Montblanc Exo Tourbillon takes its name from its unique construction that allows for the movement’s balance wheel – a large, stately looking affair with 12 screws that beats at 2.5 Hz with a blued Phillips terminal curve hairspring – to oscillate outside its traditional position in the tourbillon cage, which makes a full rotation once per minute. As you may have guessed, the “Exo” in Exo Tourbillon refers to external.

In the new Montblanc Star Legacy Suspended Exo Tourbillon Limited Edition 18, the positioning of the balance is pushed to the next level – literally. The balance has been raised precisely 3.2mm higher than the rest of the dial, where it looks to be physically suspended in mid-air from the rest of the tourbillon cage, something made possible by a dedicated tourbillon bridge with a single, curved arm.

While I have not yet been fortunate enough to go hands-on with the new Star Legacy Suspended Exo Tourbillon in hand, previous in-person Exo Tourbillon experiences have always left me slackjawed in amazement at a regulating organ that appears to be levitating by its lonesome.
Now some of you might be wondering if there is any horological benefit to the Exo Tourbillon, or if it simply looks really freaking cool.

And according to Montblanc, the answer is yes.
This is what you should tell any friends who drop the anti-tourbillon spiel on you. The Exo Tourbillon design is said to be far more energy-efficient than a conventional tourbillon execution – if there is such thing – as the cage is naturally smaller and more lightweight, thanks to the displaced balance wheel. Further, Montblanc balances the tourbillon with a pair of gold pillars to keep it running in equilibrium. And since the regulating organ is placed outside the continuously rotating tourbillon, the balance is no longer impacted by the cage’s inertia.
While the tourbillon will undoubtedly be what catches most collectors’ eyes, there are plenty of other details to appreciate. There’s a domed hour and minute sub-dial at 12 o’clock, with black Arabic numerals and a concentric snailed finish, to indicate the passing time, while the rest of the dial is rendered in stunning aventurine. A blued seconds hand is attached to the one-minute tourbillon for precise time-telling. The case is expectedly precious, crafted out of 18k white gold, with a sapphire crystal on the front and back, revealing the hand-finished, Minerva-crafted manual-wind Montblanc Manufacture caliber M16.68.

Movements from Minerva aren’t known to be aesthetically disappointing, and the one inside Star Legacy Suspended Exo Tourbillon is an excellent example of why these calibers garner such praise. Note the intricate côtes de Genève, the sumptuous chamfers of the bridges, and the location of the signature Minerva arrow on the mirror-polished pawl.

There are plenty of disappointing tourbillons out there. The new Montblanc Star Legacy Suspended Exo Tourbillon Limited Edition 18, however, is not one of those.
First introduced in 2010, the patented Exo Tourbillon complication is a key pillar of the Montblanc watch collection. The idea was to position the large balance wheel, beating at the traditional low frequency of 18’000 oscillations, outside of the tourbillon’s rotating cage. This offered a spectacular view of the tourbillon in motion while improving the precision of the timepiece.

During the Watches and Wonders digital exhibition, Montblanc unveiled its Metamorphosis and patented Exo Tourbillon in a new blue colour scheme. These key innovations marked a new chapter in the Montblanc fine watchmaking universe at the time of their release, becoming key watch pillars over the years and inspiring the development of future movements used in the Maison’s core collection.
The Montblanc Star Legacy Suspended Exo Tourbillon Limited Edition 18 perfectly demonstrates the mastery of a classic and traditional artisanal aesthetic combined with an innovative spirit.

The patented Suspended Exo Tourbillon complication was developed entirely in-house and required three years of development. The “Exo” is derived from the Greek for “external” or “outside” and refers to the large balance wheel which is positioned outside of the tourbillon’s rotating cage.

The Montblanc engineers’ idea, when developing the innovative patented Suspended Exo Tourbillon, was to create a one-minute tourbillon that would be more visible, further revealing its beauty. This particular patented construction allowed them to keep a large and impressive balance wheel, eliminating the need to increase the size of the movement or the case.
The massive balance wheel is raised 3.2 mm higher than the dial and appears to be floating above it. This suspended position has been made possible thanks to a dedicated tourbillon bridge with only one arm which is curved, creating a three-dimensional look and a fine watchmaking aesthetic.

Thanks to its asymmetric construction, the alignment of the Exo Tourbillon bridge, with its solitary arm, represents a horological challenge. The complexity of the patented Exo Tourbillon comes from the dimensions of the long axis that need to be extremely precise, along with the complication construction itself, which requires that the balance’s axis must be perfectly perpendicular to the movement.
In terms of performance, the Exo Tourbillon saves more energy than a conventional tourbillon as the cage is smaller in size and free of the weight of the balance wheel. It is also balanced by two gold pillars that equilibrate the cage. The fact that the balance is positioned outside of the rotating cage also means that it isn’t affected by the inertia of the cage.

The large balance wheel, beating at the traditional frequency of 18’000 oscillations per hour plays an important role in the performance of the timepiece thanks to its impressive 18 screws.

Following pure horological tradition, the Manufacture movement calibre MB M16.68 is entirely decorated in the Replica Montblanc Manufacture in Villeret with hand-crafted finishings such as Côtes de Genève stripes, inner angles, circular graining, beveling and a mirror-polished pawl with the hand-finished Minerva arrow.
The entirely polished 44.8 mm case comes in 18 K white gold and features a sapphire crystal on the case back which reveals the beauty of the hand-finished manually wound movement calibre MB M16.68. It also provides a totally transparent view of the Exo Tourbillon from the front to the back.

The sophisticated three-dimensional dial of the Montblanc Star Legacy Suspended Exo Tourbillon Limited Edition 18 is constructed in eight different parts that have been decorated entirely by hand using traditional watchmaking techniques.

The base is in 18 K gold and has been highlighted with a hand-made guilloché pattern in places, and a sandblasted decoration in others, with polished steps framing the different finishing techniques. A refined guilloché pattern completes the aesthetic. A silvery-white dome at 12 o’clock, with an azuré decoration in the centre, houses the hours and minutes counter, mirroring the three-dimensional effect of the outstanding Suspended Exo Tourbillon.

This exclusive Montblanc Star Legacy Suspended Exo Tourbillon is limited to 18 pieces, paying tribute to the year the Montblanc Manufacture was founded in Villeret in 1858. The timepiece comes fitted with a blue alligator leather strap and a triple folding clasp with security pushers.