Review: The New Jaeger-LeCoultre Duometre Heliotourbillon Perpetual

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Jaeger-LeCoultre – fondly known as the watchmaker’s watchmaker – are no strangers to the tourbillon. Its first tourbillon timepiece was a pocket watch from 1946, driven by the Calibre 170. The first tourbillon wristwatch by the manufacturer came almost half a century later, but it was well worth the wait. In 1993, the spectacular Reverso Tourbillon with mesmerising gold bridges made its debut, serving as a springboard from which many more innovative tourbillon pieces would rise. Indeed, there’s been all sorts of tourbillons since: flying tourbillons, spherotourbillons, gyrotourbillons, tourbillons with cylindrical hairspring – all born of watchmaking ingenuity and the cumulative experience of the manufacturer. Even ‘plebeian’ flat tourbillons by Jaeger-LeCoultre mean serious business; the Calibre 978, winner of the 2009 International Chronometry Prize with a deviation of only 0.13 seconds/day, is a case in point.

Jaeger-LeCoultre Duometre Heliotourbillon Perpetual

Despite having the know-how, there is one type of tourbillon that has so far evaded the catalogues of the Le Sentier brand – well, that is until this year. It’s been a long time coming, but Jaeger-LeCoultre finally inducts a triple-axis tourbillon wristwatch into its collection. Here, we bring you the details and our honest thoughts on the new Duometre Heliotourbillon Perpetual, a watch that is so much more than just the tourbillon.

The Case, Dial, and Hands

The Heliotourbillon Perpetual features a newly re-designed case that is almost unrecognisable compared to the old Duometre case. Inspired by the savonette pocket watches created by the Maison in the 19th century, the new pink gold case is fitted with domed sapphire crystal at the front and back. Combined with a curved bezel, they give the case a smooth, curvaceous profile that resemble a bar of soap (hence savonette). The lugs are now screw-in rather than integrated, which allows for more meticulous finissage. Indeed, the finishing on the case, like its new design, is more nuanced than ever before, with a harmonious mix of polished, brushed and micro-blasted surfaces. Even the crown has been thoughtfully redesigned to complement the new case, now featuring deep, rounded notches for better grip and a neo-vintage vibe. One of two aspects of the case that reminds us that we are still in the 21st century is the crystal window on the left flank that allows us a side view of the heliotourbillon. The second is the size; at 44 mm x 14.7 mm, it pushes the limits of wearability even for a contemporary watch.

The side window on the left flank is a thoughtful, new addition that isn’t present in the older Spherotourbillon model.

As praiseworthy as the new Duometre case is, it is the dial of the Heliotourbillon Perpetual that truly takes the breath away. Its layout evokes memories of the Spherotourbillon model: tourbillon on the openworked left, time display on the right, two power reserve displays (one for each mainspring) at 1 and 5 o’clock, and two sub-dials at 11 and 7 o’clock. That’s about as far as similarities go however. In the new Heliotourbillon Perpetual, the tourbillon in question is in fact a triple-axis tourbillon – a first for the brand. And while the Spherotourbillon displays the date radially along the perimeter of the time dial, the Heliotourbillon Perpetual does so in a more elegant, compact manner via a grand date display. Featuring a gold frame and two numerical discs visible through an aperture, the grand date allows the date to be read instantaneously and most intuitively. The two sub-dials next to the power reserve displays indicate the day and month radially, as well as the phases of the moon and the year. Yes, the Heliotourbillon Perpetual – on top of a sophisticated multi-axis tourbillon – is also fitted with a perpetual calendar. Rather cleverly, the year indication is set with a special mechanism able to highlight in red the last digit of every leap year. A Jaeger-LeCoultre patent, the special leap year display allows for further space-saving and less clutter on the dial.

The Heliotourbillon as seen through the distortion caused by the domed crystal’s curvature.

The Movement

Driving the Duometre Heliotourbillon Perpetual is the 655-part, 89-jewel in-house Calibre 388. The manually wound movement has a power reserve of 46 hours and operates at 4 Hz. The Calibre 388 is based on Jaeger-LeCoultre’s Duometre technology, invented and patented in 2007. The mechanism aims to solve an interesting conundrum in watchmaking, where adding complications to a movement poses a negative effect on timekeeping. This is caused by the added, sudden, and fluctuating demands in power supply by complications, which disrupts the consistent flow of energy to the balance needed to maintain accuracy. In its most basic form, the Duometre mechanism features two barrels and two independent gear trains – one for timekeeping, one for complications only – linked to a single escapement. The separation of power supply this way allows for a higher degree of operating accuracy, especially when a power hungry complication, say a perpetual calendar and/or multi-axis tourbillon, is involved.

If the ‘Duometre’ portion of Jaeger-LeCoultre’s latest masterpiece is its most discreet technical achievement, then the ‘Heliotourbillon’ is its most visually striking one. All eyes are inevitably drawn towards the brand’s most recently developed tri-axial tourbillon. Supported on ceramic ball bearings to minimise friction, it alone consists of 163 parts weighing less than 0.7 grams in totality. And fitted with a cylindrical hairspring – another specialty of the Le Sentier-based manufacturer – the Heliotourbillon comprises three titanium cages. The first cage is set at right angle to the balance wheel; the second is set at right angle to the first. Together, they are constrained by an axis tilted at 40 degrees and make a full rotation every 30 seconds. The third cage is perpendicular to the second and completes a rotation in one minute. The end result is a visual spectacle that aims to negate the effect of gravity on the balance.

The minute-long rotation of the third cage of the Heliotourbillon allows it to double as a seconds indicator.

The ‘Perpetual’ bit of the Duometre Heliotourbillon Perpetual is probably the most conventional part of the watch. Nevertheless, it is executed to the highest level. Jaeger-LeCoultre uses a good balance of radial and aperture displays to convey a host of information concisely. The unassuming moon phase indicator is anything but ordinary, as it will remain accurate to within a day even beyond the perpetual calendar’s scheduled adjustment in 2100. More precisely, the moon phase indicator will only deviate by a day after 122 years.

Every millimetre of the Calibre 388 is finished to exacting standards, including parts unseen. The bridges – which cover the greatest area of the case back – are adorned with sunrayed Geneva stripes that radiate seamlessly across the gaps. Their edges are hand-bevelled and polished. Though lacking in inward angles, numerous outward angles are present. The screw heads visible on the surface are either heat-blued or mirror polished. Meanwhile, the wheels are circular brushed while the main plate is decorated with perlage.

The Calibre 388 as seen through the sapphire crystal case back.

The Competitive Landscape

At the level of the Duometre Heliotourbillon Perpetual, the air is rarefied and competition is scarce. Timepieces that can match its technical ingenuity are truly few and far between – but it also means they do exist. The Duometre Heliotourbillon Perpetual is only available in one version currently: pink gold, at USD438,000. And if the price isn’t prohibitive enough, there’s also the fact that only 20 pieces will ever made.

The Duometre Heliotourbillon Perpetual is a large watch, but it needs to be so in order to afford space for the tourbillon to have an appreciable visual impact.

If a tri-axial tourbillon isn’t enough, why not try doubling the number of tri-axial tourbillons with double the speed? The Purnell Escape II Double Tourbillon has exactly this. The Calibre CP03 has six mainsprings assembled in four barrels to drive these high speed tourbillons called “Spherions”. Each weighing 0.8 g, they consist of three cages, with the inner cage completing a rotation in 8 seconds, the secondary cage in 16 seconds, and the outer cage in 30 seconds. With a starting price of almost half a million Swiss Francs and limited quantities produced, only a lucky few will be able to enjoy the Escape II Double Tourbillon.

The Purnell Escape II Double Tourbillon

For a tri-axial tourbillon watch not limited by production numbers, look no further than the Girard-Perregaux Minute Repeater Tri-Axial Tourbillon. As its name suggests, its two main complications are the minute repeater and, of course, the tri-axial tourbillon. To our knowledge, this is the only watch model in the market with a minute repeater and tri-axial tourbillon together under one crystal. And speaking of the crystal, it is domed much like the Heliotourbillon Perpetual. Quite menacingly, the Minute Repeater Tri-Axial Tourbillon is 48 mm in diameter, making it virtually unwearable by anyone without an above average wrist size. Suffice to say, the watch is more an exhibition piece, a notion further strengthened by how beautifully openworked the dial is. Also priced at around the half million mark, this titanium variant is not a limited edition, although don’t expect more than a few to be made each year.

Girard-Perregaux Triaxial Minute Repeater side view
The Girard-Perregaux Tri-axial Minute Repeater

Concluding Thoughts

Jaeger-LeCoultre have been on fire with blockbuster pieces in recent years. The Heliotourbillon Perpetual is the perfect flagship model to usher in the new direction taken by the Duometre collection. Expect new variations of the watch in the future – white gold or platinum being the most obvious next step.


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