Ladies and Gentlemen, what you are about to witness is the birth of a new chronometer by Leroy.


During the Sunday just before SIHH, I was invited by Leroy’s General Manager Olivier Müller, whom some of you might have known as the CEO of Laurent Ferrier from up until 2013, to an intimate dinner among a handful of journalists to get an exclusive look at the brand’s upcoming Chronometre Observatoire.

I honestly didn’t know much about the modern Leroy brand (which until recently was called L. Leroy), though the legacy and name should ring a bell for any seasoned horophile. I won’t bore you with history, but suffice to say that one, predating even Breguet and Vacheron Constantin. On top of that, the company actually had a continuous history from the 18th century to the 20th century. In more recent times, it was acquired by the Festina group, who also own the Perrelet brand as well as a group of subcontractors and suppliers to the watchmaking industry. This gives a small brand access to the kind of infrastructure and manufacturing prowess that’s on par with the bigger names out there.

Olivier introduced us to the team behind the Chronometre Observatoire, with award-winning designer Eric Giroud worked on the aesthetic aspects of the watch (case and dial), while Karsten Frassdorf is in charge of the movement conception and development within Leroy’s own manufacturing facilities in Le Brassus.

Leroy Chronometre Observatoire-21

Leroy Chronometre Observatoire-16


The idea for the upcoming Chronometre Observatoire was to produce a timepiece that contains elements from the brand’s namesake’s historical work, while delivering chronometer-grade performance that would be officially certified by the venerable Obesrtvatoire  de Besancon which, unlike COSC for example, tests complete watches and not just movements.

Blown away with what I had seen during the dinner, I decided to pay the folks at Leroy a visit to learn more about their new chronometer.

Now, before I show you the watch, I’d like to make it clear that this is just a functioning prototype. As such, several details are subject to change before the watch is officially presented at Baselworld 2015 next month.


Let’s start with the exterior. The case, in either 38mm or 40mm diameters and done in rose gold or white gold and palladium, features a three-part construction with a pleasant mix of polished and satin-brushed surfaces. It’s simple but sufficient. After all, this is a watch that puts the emphasis on chronometry and not ornate features.



I should however note that the crown is not a final version, though I sincerely hope they keep the same circumference in the final version.

The dial is done in solid silver, and available in a number of colors including opaline silver, blue, yellow or rose gold and slate grey. The design, although perhaps not that of a purely traditional chronometer, features a “barleycorn” guilloché pattern center and opaline circumference. The applied hour markers are done in polished white gold with a smooth, rounded surface give a sense of volume to the dial. The hour and minute hands are done in an uncommon Courteault shape with hollowed centers. I was surprised to find them easily legible.


Leroy Chronometre Observatoire-14

Leroy Chronometre Observatoire-13

The small seconds dial is done in a circular satin finish and solid hand in a solid Courteault form. The final version will have an azurage sloped edge around the circumference.


One of the more interesting features is the power reserve indicator, done in the form of a lozenge window cleverly integrated into the minutes track at 45 minutes, revealing a colored disk that replaces the marker on the 9 o’clock minute track. I’ll come back to this later.


Now let’s get to the really interesting part, the movement. Conceived by Karsten Frassdorf, know for his affinity towards larger balance wheels and alternative executions, the idea was to bring back some of the inventions by the brand’s namesake Pierre Le Roy while delivering a movement that’s truly unlike any other. On looks alone, Leroy didn’t fail with what they’ve dubbed the L200 caliber.

Again, I have to stress that the piece I handled on two separate occasions was just a prototype (albeit a functioning one), void of any proper finishing and decoration.


Featuring no less than 42 jewels, the movement is certainly on the larger side at 15 lines, though in my opinion this is always a good thing, especially when it comes to creating balanced dial layouts. It remains relatively slim however with a height of 4.5mm.  One of the features you don’t see on the prototype movement is the stop-seconds mechanism.

Leroy Chronometre Observatoire-17

At this point, you’re probably asking yourself, “what on earth is that tourbillon-looking escapement?”

And as well you should, as the escapement is without a doubt the most exciting feature of the Leroy Chronometre Observatoire. Housed within a screwed cage called a “Brun” cage, invented in the 1900s by watchmaker M.J. Brun, the escapement is quite exceptional. It incorporates several elements from Pierre Le Roy’s work, with the first being the direct impulse escapement.

Leroy Chronometre Observatoire-movement

The large balance wheel features a hairspring with two terminal curves, one interior and the other an exterior, which supposedly provides better isochronism in a perfectly concentric manner, even in a vertical position. Pierre Le Roy had come to the conclusion that each spiral has a unique length that provides perfect isochronism of the hairspring. For this reason, the 360° Brun cage was incorporated to allow the watchmaker to choose the exact point of attachment of the hairspring’s exterior terminal curve.

Leroy Chronometre Observatoire-escapement

Leroy Chronometre Observatoire-18

It’s also worth noting that the direct impulse escapement’s pallet lever features 4 synthetic diamond jewels instead of rubies, for better durability and longevity.

Given the sheer size of the balance wheel and hairspring, the slower frequency of 2.5Hz is to be expected. One of the visible effects from such an execution however is the behavior of the seconds hand, where it performs what’s known as a “Duplex jump” in a one-second period it will move in two increments, where you have one smell step followed by a large one. I was told that the small seconds scale would be redesigned to reflect this.

The movement features two barrels that work in parallel rather than in tandem, to optimize the low frequency pressure of the escapement. The watch will have a power reserve limited to 98 hours via a stop mechanism, even though its has a theoretical power reserve of 150 hours. This is to ensure optimal isochronism throughout the power reserve.

Leroy Chronometre Observatoire-7

It is for this reason that the power reserve indicator on the dial features a multi-colored disk, with the dial’s color indicating a full power reserve down to about 38 hours, followed by from 38 hours then finally red for the last eighteen hours of power left. This is intended to motivate the wearer to wind the watch daily.

All in all I think Leroy have finally hit the mark in coming out with a piece. I’m curious to see the final version next month at Baselworld, and to see how the movement will actually perform in the long run. I’ve always been a bit skeptical of low-frequency movements with extra-large balance wheels, but it looks like Leroy might just make me think otherwise.

Leroy Chronometre Observatoire-20

While the pricing hasn’t been confirmed, I was told to expect a retail price of CHF 35’000.

I’d like to thank Olivier Müller and Karsten Frassdorf for their hospitality at the Leroy manufacture and for taking the time to go through some of the Chronometre Observatoire’s finer details to me.

More to come about Leroy and the Chronometre Observatoire at Baselworld 2015. For now you can look for official information to be revealed soon on