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Review: The Jaeger-LeCoultre Duometre Chronograph Moon

Which was your favourite release of Watches & Wonders 2024? For me, one of the real standout pieces of this year’s show was the new Duometre Chronograph Moon, and I’ve got one right in front of me. Shall we take a closer look?


There are few brands as well respected in the watch industry as Jaeger-LeCoultre. Affectionately dubbed “The Watchmaker’s Watchmaker”—as the brand produced movements for the likes of Patek Philippe, Audemars Piguet, Vacheron Constantin, and many more—Jaeger-LeCoultre has spent 191 years chasing timekeeping excellence while proving it can do what most can’t.

The biggest issue with complications like the chronograph is that they’re power-hungry little mechanisms that draw additional power from the watch. This means that every time you activate and use the chronograph, you interrupt the constant supply of power needed for the escapement to do its job and keep time precisely. For most, this is simply understood. But Jaeger-LeCoultre aren’t most. The Watchmaker’s Watchmaker sought a solution to the problem, and that’s where the Duometre mechanism comes into play.

Introduced in 2007, the Duometre mechanism sees the integration of two separate barrels with two independent gear trains into one watch. Looking at the back of this watch—with the two barrels at the top—the train on the left is for the chronograph, and the train on the right is for the time and any remaining functions of the watch. The two are then linked together to a single regulating organ. This separation means that the activation and use of the chronograph will have no effect on the overall timekeeping of the watch, thus creating a solution to our problem.

This new Duometre Chronograph Moon takes that concept and ups the ante with a load of additional complication. Let’s work our way around the dial. Within the hour and minute sub-dial, to the left, is a day/night indicator. Then we have a moonphase, placed amongst the chronograph hour and minute sub-dial to the right. Underneath those is a 1/6th of a second foudroyante counter, which works in conjunction with the central seconds chronograph hand and is controlled by a single pusher at two o’clock. And finally, two power reserve indicators—one for each barrel—that have been open-worked. A lot is going on here, and yet the watch remains legible.

Now, you might be expecting this thing to wear like a wall clock on the wrist, given the Calibre 391’s 482 parts, but I’m pleased to say it doesn’t. The Chronograph Moon—available with either a pink gold or 950 platinum case—has a 42.5mm diameter and 14.2mm thickness, which makes it rather wearable despite its complexity, at around the same size as a Calibre 3861 Moonwatch.

Speaking of the case, this year, the Duometre’s case has been redesigned, taking inspiration from the savonette pocket watches Jaeger-LeCoultre produced throughout the 1800s. The French word savonette means: “a small disc of soap, with rounded contours, that can be cradled in the palm of a hand”, and while I wasn’t expecting to hear that either, you can definitely see the influence here. The shape of the 34-part case, the rounded bezel, and the convex crystal all help to aid the savonette aesthetic, with the polished edges of the lugs being the only hard line in sight.

But it wouldn’t be a Jaeger-LeCoultre review without mentioning finishing, would it? While the aforementioned savonette-style case receives a mixture of brushed, polished and micro-blasted surfaces, allowing the watch to catch and play with the light in different ways, the real stars of the show here are the dial and movement.

Starting with the dial. Away from the pink gold applied JLC logo, numerals and hour markers, the sectored dial itself is worth paying a little more attention to. The main surface of the dial—along with the centre of each sub-dial—has an opaline finish with a powder-like texture. In contrast to that, helping to increase legibility, the remaining surfaces of the sub-dials are decorated with azure, an engraving technique, which, in this case, gives the sub-dials a consistent circular pattern. The sub-dials are then sunken slightly below the surface of the dial, the power reserve indicators are given a brushed finish, and the edge of the dial is curved to compliment the contours of the glass box crystal above.

Flipping the watch over reveals the all-new Calibre 391. The 50-hour calibre—50 hours for each barrel and gear train—is as much a visual treat as it is a technical one. Amongst all the levers and gears, the movement is decorated with a mixture of brushed and polished surfaces, perlage on the mainplate, blue’d screws, bevelled and polished edges to the bridges, and sunray Geneva striping. Sunray Geneva striping, gives the movement its radiating effect away from the balance to the edge of the movement, achieved by individually decorating each component.

Fun fact about the Duometre: when you need to top up the power, you do so with a single crown. Turning the crown forwards will wind the time barrel, and backwards will wind the complication barrel. Genius.

At this point, you’re probably wondering how much this will all cost you. I haven’t mentioned the price until now, so it must cost an arm and a leg, right? Well, sort of, but maybe just the arm. This pink gold watch does cost a lot of money—£66,500—but I bet you were expecting me to say more. The engineering, the complication, the brand … all would lead you to believe the watch costs at least double that, but it doesn’t.

What do you think of the new Duometre Chronograph Moon?

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