New: Rudis Sylva Harmonious Oscillator RS 23

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We have been quietly following Rudis Sylva for many years. And now, they have updated their Harmonious Oscillator with the new RS23.

Press Release details with commentary in italics.

New: Rudis Sylva Harmonious Oscillator RS 23

The retail price, direct from manufacturer of Rudis Sylva Harmonious Oscillator RS 23 is CHF 90,000 in rose gold and CHF 80,000 in titanium.


We have always been impressed with the works of Rudis Sylva. This relatively low key manufacturer has been producing top notch finishing on their watches since we were first introduced to them in Baselworld by none other than Philippe Dufour.

The Harmonious Oscillator is a unique escapement which uses a special technical execution to eliminate the effects of gravity on the escapement. As we understand it, the system is not dis-similar in concept to what is used by Dufour in his Duality and also by Greubel Forsey in their multi-tourbillon series. Technically, we think, we need to verify with Rudis Sylva and other watchmakers, that the technique used is not the same as that of the F.P. Journe Chronomètre à Résonance or that of the Armin Strom Mirrored Forced Resonance.

The escapement has measurable performance which is better than a tourbillon. As can be seen in the graphs below, the fluctuations to the beat rate is kept at an even zero with the Harmonic Oscillator over time, but even a well designed and regulated tourbillon shows considerable rate changes. The Harmonic Oscillator achieves this impressive result by using the opposing balances to cancel out each other’s rate errors to produce a zero deviation. This is also achieved simultaneously while in the tourbillon, it takes 60s to normalise the fluctuations caused by gravity.

We first discussed the Harmonious Oscillator RS10 and the concepts behind the invention here. The latest piece is now the RS 23, released this year. The novelty is stated by Rudis Sylva as a simplified form of the original harmonious oscillator, and is also reflected to the lower pricing of CHF 90k in gold vs CHF 250k for the RS 16 in gold. The released photographs, alas only two, show two magnificently beautiful watches.

We are in discussion with Jacky Epitaux to be examine the new RS 23 in detail, both to understand what has gone into simplify the movement and also to photograph the watch. Hope this will happen soon, and will update with a new comprehensive explanation article when we do.

Release details Rudis Sylva Harmonious Oscillator RS 23.

An invention as important as the Breguet Tourbillon” “Better than a Tourbillon”
“The Tourbillon reference”

These are just some of the comments from master watchmakers and industry journalists since the Harmonious Oscillator was created!

This patented invention with two toothed balances immediately cancels out the effects of gravity when a watch is in the vertical position, unlike a conventional Tourbillon, which needs a whole minute to do so.

Hailing from the Jura Arc, the brand unveiled its invention at Baselworld in 2009. Watch enthusiasts rushed to discover this toothed-balance movement, which is based on technology that goes against all established watchmaking theories. An examination of this revolutionary device reveals the subtlety of the system with two balance-springs which are set in opposition and deploy in turn.

The negative chronometric value of one spring balance is compensated for simultaneously by the positive value of the other spring balance, which totally cancels out the effect of the Earth’s gravity on the precision of the watch.

RS 23, the natural next step for the Harmonious Oscillator

Today, Rudis Sylva is launching a simplified version of the Harmonious Oscillator which is, nonetheless, equally effective in terms of combating gravity.

The toothed, geared balances are fixed and no longer rotate once per minute in a 360-degree cage as in the “Tourbillon” version.

This simpler execution with two connected balances also allows all chronometric anomalies caused by the Earth’s gravitational pull to be cancelled out simultaneously, and therefore remains more precise than a conventional Tourbillon which needs 60 seconds to compensate for the effects of gravity.

Rudis Sylva, a name with Latin roots

Rudis from Ruedin Jean, the pioneer born in Franches-Montagnes around 1400, and Sylva, the forest.

Rudis Sylva is the old name for the Swiss village of Les Bois in the Franches-Montagnes district, 12 km from La Chaux-de-Fonds. In 1900, some 600 of its 1450 inhabitants were watchmakers! The first recorded watchmakers in the village date to 1750. The most well- known of these are the Clémence and Baume families, who opened stores in London to sell their products, which included timepieces with chimes. The Rudis Sylvains – as inhabitants of the village Les Bois were known – passed on their watchmaking expertise throughout the Jura area over many centuries.

Exceptional finishes

The Harmonious Oscillator is a patented movement developed solely by the brand. Whilst the movements are, first and foremost, technical by nature, they are also all decorated by hand, showcasing the skills practised by the craftspeople of the Jura for centuries. When the brand was created, it was the regional expertise that was showcased rather than that of any specific watchmaker.

A Rudis Sylva watch merits a magnifying glass!

This reveals the magnificence of the guilloche work, engraving, bevelling in the inward corners, sunray or circular graining decoration and the other finishes that enhance the Harmonious Oscillator.

Guilloche work

Hand guilloche work has been showcased since the very first Rudis Sylva collection in 2009. The ever-decreasing pyramids designed by Georges Brodbeck, another neighbour from Franches-Montagnes, are extremely difficult to create, and lend prestige and elegance to the RS 10, RS 12 and RS 16 collections.

The “Legendary Brodbeck”, as he was affectionately known by his colleagues at the Technicum in La Chaux-de-Fonds (who claimed he was such a gifted engineer that he could dismantle then reassemble his moped during break time), has created a “flinqué” decoration for the RS 23 collection.

This particular type of guilloche work is created with a special turning engine equipped with various roses which enable a multitude of decorations to be made. This finish is used to enhance the bridge of the Harmonious Oscillator. The engraving is done by hand and using an endmill; the bridges are also hand-bevelled and, apart from the escapement, the barrel springs and the jewels, all the components are machined expressly for the Rudis Sylva calibre.

Rudis Sylva, utterly different and utterly exclusive!

The Jura-based brand is a lesser-known – an exceptionally exclusive – gem! Its DNA has roots in numerous sources:

The name of the brand comes from the village of Les Bois, located in the cradle of Swiss watchmaking, where several of the industry’s leading lights were born. We can cite the Baumes (which became Baume & Mercier), the Clémences, owners of stores in London, the Huots, which became Nivarox-Far, the Baumanns, which became ETA, and other families famous far and wide.

The Harmonious Oscillator, developed and made more reliable between 2006 and 2010, has been patented and garnered huge acclaim from master watchmakers. It is considered by some as a key invention in the quest for accuracy.

Rudis Sylva decided to develop its movement in its entirety. It is rare for independent brands to create an entire movement. They generally purchase a base calibre that they transform, using an existing mechanism with tried and tested reliability.

Those involved with the brand are native to the cradle of watchmaking and can rely on a network of renowned skills. They are the descendants of the region’s “watchmaking farmers” or “window watchmakers“, as they used to be known; they are humble by nature, and are driven by a never-ending quest for true craftsmanship.

Watches and Wonders 2023

The new RS 23 was unveiled at the Watches and Wonders trade fair which the brand attended for the second time. Within the “Carré des Horlogers”, an environment conducive to innovation, Rudis Sylva was able to allow its hosts to discover a Harmonious Oscillator that was different to – yet as appealing as – the previous models.

Almost 15 years on from the launch of its first timepiece, the brand has created a new simplified version that is just as appealing as the previous models. The RS 23 collection is available in a rose gold or titanium case, and is released in a limited edition of 8 pieces of each.

The finishes are “Haute Horlogerie” grade, and the eclectic clientèle will find in this timepiece all the design codes showcased since the brand was launched and mentioned above.

Harmonious Oscillator RS23

Case: pink gold 18k or titanium

Width: 44mm
Height with glass box Case finish: 12.9mm
Inter-horn distance: 23mm

Back: pink gold or titanium, screwed

Engraving by hand Decoration sand finished, galvanic grey or brown

Strap aligator, large scales with tassel, brown or black
Buckle tang buckle in pink gold or titanium Crown
Brand logo 3 pine trees on 3 mountains symbilising the setting of the Jura, circa 1350


Decoration rose gold 5N plated and blue


Dimensions: diameter 39.55mm, 7.78mm hight
Winding: manual, 49 crown revolutions
Power reserve of 72 hours

Harmonious Oscillator Technical Specifications

System unique worldwide, patent no. 700747

Balances: toothed, interlinked, ensuring the same amplitude.

Escapement: only 1 with 1 pallet fork positioned at 90 degrees
Frequency: 21,600 bph
Balance-spring symmetry and energy is constantly opposed with instantaneous elimination of vertical gravity effect

Movement finishes

Main plate: sand blasted with bevelling
Bridges: hand decorated bevelling and sanding
Gear train: circular graining with diamond polished corners
Barrel drum: snailed
Rudis Sylva bridge: brushed and bevelled, with 1 inward corner
Balance cock, over the Oscillator: brushed and bevelled with 1 inward corner Main plate: sand decorated and hand bevelled

Oscillator bridge decoration: hand guilloché, flinqué