Only Watch 2023: Bernhard Lederer Central Impulse Chronometer

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Bernhard Lederer Central Impulse Chronometer

For the first time since inventing the Central Impulse Chronometer, watchmaker Bernhard Lederer unveils a unique version without a dial: the movement is completely exposed under the crystal. It is also the first model to be offered at auction. True to the innovative ambitions of each of his creations, Bernhard Lederer’s intent for Only Watch 2023 was to design a timepiece with a profoundly reworked aesthetic, first laid bare then imbued with colour. This also marks the return of the great watchmaker to Only Watch after 12 years.

Bernhard Lederer Central Impulse Chronometer

It was in 2020 that the very discreet Bernhard Lederer once again found himself propelled to the forefront of the watchmaking scene. As much respected by major collectors as he is reserved, he presented a movement of rare ingenuity that built on the foundations first laid by Breguet and further developed by George Daniels.

Breguet, Daniels, Lederer. The nineteenth, twentieth and twenty-first centuries. Three men, three centuries, and the culmination of a long and deep journey to the heart of the mechanical watch: its escapement.  

Though it is not necessary to understand the Central Impulse Chronometer to grasp the singular nature of the timepiece created for Only Watch 2023, it is worth touching on its foundational principles. Why? you might ask. Because, for more than 400 years, the escapement has been the focus of watchmaker’s attention. It alone ensures a watch runs smoothly and keeps time precise. Some believe that, since the Swiss lever escapement is used in almost all modern mechanical watches, the matter is closed. Not so Bernhard Lederer, who chose to follow through on Breguet’s brilliant intuition that a bidirectional detent escapement would be more efficient.

Bernhard Lederer Central Impulse Chronometer

An innovative solution

With the detent escapement, the impulse is delivered as directly as possible from the escape wheel to the balance wheel. For pocket watches, Breguet had devised a system with two escapement wheels – operating alternately and therefore linked by a pair of additional, energy-hungry wheels – known as the Échappement Naturel (French for Natural Escapement. 150 years later, George Daniels picked up the torch for his own pocket watch creations, notably the Space Traveller I and Space Traveller II. This escapement, however, operated at a low frequency of 2 Hz well-suited for pocket watches. Also, you had to twist the watch to get it going.

Bernhard Lederer first raised the frequency of his escapement to the level required for reliable operation in a wristwatch: 3 Hz. Most importantly, he sought a solution which, thanks to its geometry, would force the two escapement wheels to interact in such a way as to ensure optimum chronometric operation in any everyday situation. Lederer’s patented invention aligns the transmission of the impulse to the balance wheel along a centerline, hence the name of his watch: Central Impulse Chronometer.

Bernhard Lederer Central Impulse Chronometer

What’s more: Bernhard Lederer introduced the constant force remontoire into his escapement concept. This winding organ accumulates energy upstream of the escapement, ensuring it is evenly released and delivered. The Central Impulse Chronometer has two of them, each with its own gear train and barrel.

Combining two remontoires with the escapement is unique in the history of watchmaking. The result is extraordinary chronometric performance and outstanding frequency stability, as certified by the Besançon Observatory and the COSC (Contrôle Officiel Suisse des Chronomètres).

Bernhard Lederer Central Impulse Chronometer

For Only Watch 2023: the Central Impulse Chronometer, fully revealed.

Today, the timepiece created for Only Watch 2023 reveals Lederer’s ingenious invention with a major first: the mechanism, turned on itself to offer a full frontal view, can be fully taken in by the beholder’s gaze. What was visible from the case back now appears at the front. Instead of a dial, an entire mechanism, fully exposed, without the slightest portion of it hidden from view. The sole collector of this exceptional creation will be able to tell time directly from the movement.

Those familiar with Bernhard Lederer’s work will not be surprised. If he spent decades honing his craft over decades in the realm of clocks, it is precisely because of his predilection for revealing to collectors the intimacy of his works, his passion for mechanics, their movement, their beating heart. This same philosophy finds its expression here in the Central Impulse Chronometer Only Watch 2023.

Bernhard Lederer Central Impulse Chronometer
Bernhard LEDERER / Lieu : Saint-Blaise – Neuchâtel – Suisse / Droits d’utilisation uniquement pour MHM & LEDERER WATCHES

Avant-garde character meets remarkable symmetry. It is a watch that weaves an unexpected connection between the watchmaking past, from which it draws its inspiration, and the very contemporary approach that Bernhard Lederer expresses here, as a craftsman-artisan who is  100% independent and free (and one of the very few to make almost all his components in-house, including the hand-crafted watch hands). The Central Impulse Chronometer Only Watch relays the message of innovation handed down to us by the founding fathers of Haute Horlogerie, whose legacy Bernhard Lederer sees himself a guardian of.

A project reserved for Only Watch

Many enthusiasts have asked Bernhard Lederer to develop such a variation of his Central Impulse Chronometer. The watchmaker steadfastly resisted the entreaties, reserving the very first piece for Only Watch. The last time one of his creations was offered at this famous auction was in 2011.

Bernhard Lederer Central Impulse Chronometer

For this timepiece, the entire movement, including the bridges and main plate, is treated with a black diamond-like coating. The effect is stunning, yet sacrifices none of the finishes Bernhard Lederer holds dear – notably, satin-finished, sand-blasted, brushed surfaces and polished angles. For this unique piece, everything has been executed by hand, throughout the monochrome composition.

But is it really monochromatic? Not quite. Indeed, the Central Impulse Chronometer movement catches the eye with a dozen sectors in vivid colours generated with a Super-LumiNova® coating – they reflect the 2023 Only Watch colour chart, with vibrant blue, pink, yellow and green, among others. They also make the letters forming the word “SIX” at 6 o’clock and “TWELVE” at 12 o’clock pop.

Bernhard Lederer Central Impulse Chronometer

At the case back, Bernhard Lederer projects a very modern abstraction of Swiss landscapes between lakes, mountains and urban backdrops – interlacing colours and spatial volumes, boldly applied marquetry, each surface given its own grain, defining it in space and capturing light in its own way.

There are no pastels or gradations in these colours. The tones are deliberately vivid, playful and sparkling. The idea is to flirt with impertinence between the rigour of a very high-level movement and its beguiling, surprising and unique presentation. The art of being serious… without taking oneself (too) seriously. An approach in perfect harmony with the spirit of Only Watch: a charity auction of exceptional timepieces, but one that never loses sight of the children for whom it is intended, bringing them as much joy as hope.

Bernhard Lederer Central Impulse Chronometer Technical Specifications

Reference: CIC 9018 – Only Watch 23


  • Hours, minutes


  • Mechanical hand-wound
  • Number of components: 220
  • Number of jewels: 46 jewels
  • Frequency: 21,600 alternations/hour (3 Hz)
  • Diameter: 39.3 mm
  • Thickness: 5.98 mm
  • Special features:
    • Double barrel,
    • Two independent gear trains,
    • Two constant force winding mechanisms,
    • Mirrored chronometer escapement with central impulses,
    • Variable inertia balance with eight inertia weights,
    • Breguet balance spring with terminal curve.
  • Finishes:
    • The components are decorated on all sides.
    • Fine satin-finishing, top and bottom hooping, bead-blasting, hand-polished inside corners; bridges and plate straight-grained and beveled by hand on both sides.
      Super-LumiNova® coating with Only Watch 2023 colours.
  • Power reserve: Minimum 38 hours


  • Stainless steel, black DLC treatment, Super-LumiNova® coating with Only Watch 2023 colors.
  • Diameter: 44 mm
  • Thickness: 11.5 mm
  • Case back: Open with sapphire crystal, anti-reflective coating
  • Water resistance: 3 ATM


  • No dial


  • Multi-colored with original Only Watch 2023 motifs

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