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Jaeger-LeCoultre’s Calibre 985 combines a flying tourbillon, perpetual calendar and rare cylindrical hairspring in a single breathtaking display of high-complication watchmaking. Now re-imagined in stunning pink gold and platinum with dial colours to match, it brings this technical marvel to life in two striking new editions!

The watchmaker’s watchmaker, Jaeger-LeCoultre’s pursuit of precision, has been an obsession for decades. Driven by the values of Jaeger-LeCoultre’s founder, Antoine LeCoultre, his fascination with accuracy in the design and structure of the calibres, the finishing of the dial and cases, has inspired every succeeding generation to continue this same journey.

Developed in 2013, Calibre 985 is a fine example that embodies the brand’s innovative spirit and its quest for precision. The caliber 985 incorporates a flying tourbillon with a cylindrical hairspring, while also incorporating the complexity of the perpetual calendar into the movement, a concept that was rooted in 19th-century watchmaking. While combining a tourbillon with a perpetual calendar complication isn’t certainly new, what makes the Calibre 985 stand out is the design of its balance wheel hairspring.

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Jaeger-LeCoultre is one of the few manufacturers in modern watchmaking that is able to design and shape its own hairsprings in-house. Drawing on years of research into tourbillons and hairspring geometries, Jaeger-LeCoultre was able to take a largely forgotten cylindrical form hairspring that was developed in 1776 and bring it to the 21st century. In order to arrive at this shape of cylindrical form for the hairspring, however, Jaeger-LeCoultre had to develop a deep understanding of how the shape affects the accuracy of the watch.

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“The expansion and contraction of the hairspring controls the back-and-forth oscillations of the balance wheel, and it is crucial that these oscillations are concentric in order to limit the impact of both gravity and magnetism.”
Jaeger-LeCoultre on hairspring research.

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The engineers at Jaeger-LeCoultre discovered that the shape and the attachment (terminal curves) of a hairspring determine he way it contracts and expands. They also determined that various shapes of the hairspring oscillate differently. This insight prompted the engineers to develop hairsprings in different shapes, including S-shape, spherical, semi-spherical, and cylindrical forms. They concluded that the 18th century cylindrical design, whereby he ends of the spring coil inwards, offered enhanced isochronic performance, “beating concentrically in every position, regardless of the amplitude (the back-and-forth swing of the balance wheel) or remaining power reserve.” This is the hairspring design that has been implemented on the Calibre 985 movement.

While the Master Grande Tradition Caliber 985 has seen various iterations throughout the years, the 2025 update brings a fresh new look with two new case materials. Firstly, the beautiful warm glow of the pink gold case is perfectly complemented by the brown dial, while the platinum case offers a cooler feel with the contrasting rich blue dial. There is also a third option, where the platinum case is fitted with diamonds to not only enhance the luxury factor but also give a shimmering appearance.

Case Design

As mentioned previously, Jaeger-LeCoultre is presenting the case in three variations: 18-carat Pink Gold 750/1000, Platinum 950/1000, or Platinum 950/1000 with bezel set with 72 baguette-cut diamonds (3.4 carats). The 42mm x 13.27mm thick case is described by Jaeger-LeCoultre as “sophisticated in design and complex in structure”, and understandably so, as the Master Grande Tradition case consists of more than 80 components.

This case design is reserved for only the highest and most complex calibre by Jaeger-LeCoultre. This is a case that immediately signals to you that you’re handling one of Jaeger-LeCoultre’s showcase pieces, not just another dress watch with complications, but something that has been built to highlight all the technical wizardry that is going on inside. With the various surface finishes, from brushed to the mirror polish, each surface has been carefully planned to catch the light and draw the eye toward the movement’s details

Dial Design

The dial, just like the case, has its own unique design as it has been constructed on two levels separated by a hand-bevelled bridge. The area surrounding the tourbillon is set below the rest of the dial, which gives the dial a layered and three-dimensional construction. The dial features subtle finishes that enhance the overall aesthetics, from the minute track on the outer part of the dial with it micro-blasted finish to the inside of the sub-dials done in opaline finish, which gives the appearance of different hues depending on the lighting angle.

As the Calibre 985 movement is focused on precision, this is further emphasized with the seconds being indicated on an arc-shaped 20-second scale below the tourbillon aperture, with the three blued hands of the tourbillon cage each measuring a 20-second interval, with the tourbillon completing a full rotation every 60-seconds! If the design and execution of this timepiece wasn’t enough, the dial colours are just as breathtaking. The two colours range from deep sunburst blues to warm silver-opaline and grained finishes, each being carefully chosen to highlight the stunning flying tourbillon display and the perpetual calendar sub-dials.

Movement

Entirely developed and produced in-house by Jaeger-LeCoultre, the Calibre 985 is a masterpiece that is composed fo 431 parts, of which the flying tourbillon alone consists of 83 components. The cylindrical hairspring movement is able to deliver precise and consistent timekeeping, with minimal effects from gravity and magnetism. The movement powers the perpetual calendar complications, which include the month and year (shown through two apertures) in the 12 o’clock sub-dial, the day of the week and moonphase indicator (accurate to 122 years) shown through the 3 o’clock sub-dial, and lastly the 9 o’clock sub-dial, which shows the date indicator. The technical features of the movement include a 45-hour power reserve while operating at a high frequency of 4Hz (28,800 VpH).

Flip the case over, and you are treated to the Haute Horlogerie finishes on the movement. With high precision being the theme of this timepiece, the detailed finishing is just as impressive as the mechanics themselves. From the blued screws, sunrayed Côtes de Genève to the snailing and hand-bevelling, Jaeger-LeCoultre has shown an exceptional level of detail to match this masterpiece of a creation. The final touch is the 22-carat rose gold (916/1000) winding rotor, which has been decorated with sunray engravings, with the imagery of the reproduction of the gold medal awarded to Antoine LeCoultre at the 1851 Great Exhibition in London. As Jaeger-LeCoultre states, Antoine received this medal for “his development of precisely calibrated stamping, cutting machines, and mechanical lathes which allowed the components’ interchangeability.”

Initial Thoughts

This is high-complication watchmaking at its finest. The Calibre 985 brings together a flying tourbillon, perpetual calendar, and a rare cylindrical hairspring that, in a way, feels more like a living machine than a dress watch. The beating heart of the watch, the flying tourbillon, is beautifully decorated in gold, which perfectly complements both new dial colours. The blue and gold are perfect contrasts of each other, being a stunning visual spectacle for the eyes, while the brown dial subtly echoes the tones of the tourbillon cage itself, drawing your eye back to its constant rotation.

What surprised me the most about this timepiece is just how well it has been thought out, not just with the design but also with comfort on the wrist. While some haute horlogerie timepieces go all out on the design, movement, and aesthetics, they forget that they need to be wearable too. The case of the Master Grande Tradition Caliber 985 may be of intricate design, but at 42mm with angled lugs, it’s well-positioned to sit comfortably and hug the wrist. The dial layout is also clean, with three simple sub-dials showcasing the complexity of the perpetual calendar, while the tourbillon cage takes centre stage at the bottom in what is a balanced and well-proportioned design. The Master Grande Tradition Caliber 985 manages to be both a technical masterpiece and a wearable statement. It’s a reminder that even at the top of its game, JLC can make a high-complication watch that doesn’t feel untouchable.

Specification: Jaeger-LeCoultre Master Grande Tradition Calibre 985 (Ref: Platinum 950/1000)

Australian Recommended Retail Price: Price upon request.

Availability: For more information, please head to Jaeger-LeCoultre.com.au

Specification: Jaeger-LeCoultre Master Grande Tradition Calibre 985 (Ref: Platinum 950/1000 – Diamonds)

Australian Recommended Retail Price: Price upon request.

Availability: For more information, please head to Jaeger-LeCoultre.com.au

Specification: Jaeger-LeCoultre Master Grande Tradition Calibre 985 (Ref: Pink Gold 18k – 750/1000)

Australian Recommended Retail Price: Price upon request.

Availability: For more information, please head to Jaeger-LeCoultre.com.au