Bianchet Carbon Tourbillon B1.618 Openwork

De divina proportione – Bianchet Carbon Tourbillon B1.618 Openwork

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The independent brand Bianchet is offering an interpretation of the golden ratio (the divine proportion) to be enjoyed on the wrist. Although a first look might not reveal the true potential, the organic, natural details that make the Bianchet Carbon Tourbillon B1.618 Openwork, the watches will reveal themselves to any eye keen for details, keen for perfection. To skip the introduction section, just use the table of content to jump to the desired section.

Bianchet Carbon Tourbillon B1.618 Openwork

The act of creation is a sacred opportunity for any human being to be closer to nature, and to create a bridge towards divinity. It is the most rewarding feeling to be able to transform thoughts and matter with a result. When this materialises in an actual object that can be seen and admired, the result of your creation receives another status. When others can also enjoy it – one can say it is for the benefit, not just of himself, but also for others. Many dark ages of humanity and obtuse minds (unfortunately even now), consider the act of creation and enjoying human creations as the ultimate sin – an act of defiance against divinity, against your creator. But understanding the true meaning of life reveals a duty to create, as an act of worshipping and following the ultimate creator. One does not defy God by creating but merely tries to seek perfection in a way of getting close to divinity. Defying would be not using your mind and talents to bring joy, ease or cover basic needs for you and others.

Bianchet Carbon Orange Tourbillon B1.618 Openwork

The golden ration (Author Stephan C. Carlson – for Britannica)

The golden ratio, also known as the golden section, golden mean, or divine proportion, in mathematics, the irrational number (1 + Square root of√5)/2, often denoted by the Greek letter ϕ or τ, which is approximately equal to 1.618. It is the ratio of a line segment cut into two pieces of different lengths such that the ratio of the whole segment to that of the longer segment is equal to the ratio of the longer segment to the shorter segment. The origin of this number can be traced back to Euclid, who mentions it as the “extreme and mean ratio” in the Elements. In terms of present day algebra, letting the length of the shorter segment be one unit and the length of the longer segment be x units gives rise to the equation (x + 1)/x = x/1; this may be rearranged to form the quadratic equation x2 – x – 1 = 0, for which the positive solution is x = (1 + Square root of√5)/2, the golden ratio.

The ancient Greeks recognized this “dividing” or “sectioning” property, a phrase that was ultimately shortened to simply “the section.” It was more than 2,000 years later that both “ratio” and “section” were designated as “golden” by German mathematician Martin Ohm in 1835. The Greeks also had observed that the golden ratio provided the most aesthetically pleasing proportion of sides of a rectangle, a notion that was enhanced during the Renaissance by, for example, the work of the Italian polymath Leonardo da Vinci and the publication of De divina proportione (1509; Divine Proportion), written by the Italian mathematician Luca Pacioli and illustrated by Leonardo.

The golden ratio occurs in many mathematical contexts. It is geometrically constructible by straightedge and compass, and it occurs in the investigation of the Archimedean and Platonic solids. It is the limit of the ratios of consecutive terms of the Fibonacci number sequence 1, 1, 2, 3, 5, 8, 13,…, in which each term beyond the second is the sum of the previous two, and it is also the value of the most basic of continued fractions, namely 1 + 1/(1 + 1/(1 + 1/(1 +⋯.

In modern mathematics, the golden ratio occurs in the description of fractals, figures that exhibit self-similarity and play an important role in the study of chaos and dynamical systems.

Bianchet Carbon Orange Tourbillon B1.618 Openwork

Emmanuelle & Rodolfo Bianchet are part of those people that understand that perfection is all around us. The couple behind the independent brand Bianchet Watches are “guilty” of just observing the laws of nature and using the creative process to bring part of this perfection to the wrist. That is why, the Bianchet Carbon Tourbillon B1.618 Openwork is not just a sum of rounded lines, but a watch that is destined by the laws of nature and evolution to be liked, loved and enjoyed. You cannot escape it…

I have to admit, my first encounter with Bianchet watches at Baselworld was done under the preconception of “just another independent”, “just another tourbillon”… I failed to really look, to give it a chance to discover its true nature. And I forgot about it for two years. Part of the guilt was my ignorance, part was my “ability” to just forget things. Last year, during Geneva Watch Days, I had the opportunity to sit and chat with Rodolfo, get my hands on the watches and observe them. It is one thing to just like a watch, but to discover the reasoning, the complexity of why you find an object so appealing – mind-blowing…

This year, I met Emmanuelle & Rodolfo again during GWD and took some more time to even better understand the watches, the brand and their values.

Bianchet Carbon Tourbillon B1.618 Openwork

Tonneau-shaped watches – a natural shape for the wrist

The Bianchet Carbon Tourbillon B1.618 Openwork comes in a tonneau case measuring 43 x 50 x 13 mm. The thickness, combined with the rounded shape of the watch will ensure comfortable wear for a wider range of wrist sizes. And by the way, the combinations of arches found on the Carbon Tourbillon B1.618 respects the golden ratio. Nothing is left to chance but well calculated to fulfil the “divine number”.

Carbon Tourbillon B1.618

The case is manufactured from an innovative material: titanium-dust-infused Carbon – offering the lightness and robustness of both materials intertwined in a spectacular appearance. The light’s playing contrast offered by the titanium particles surrounded by the naturally dark forged carbon is equalled only by the organic look of the composition – a new chance to notice the natural patterns created by the manufacturing process.

Bianchet Carbon Tourbillon B1.618 Openwork

The Bianchet Carbon Tourbillon B1.618 Openwork case is enriched with a touch of colour from the natural vulcanised rubber insert. The inserts draw attention to the three distinctive parts of the case: bezel, caseband and caseback. The crown manufactured in titanium receives the same colour rubber insert. On this component, the handling is increased by the natural grip of the material. The rubber used on the crown is nicely shaped with a sporty pattern, very well chosen for this daring piece.

Bianchet Carbon Tourbillon B1.618 Openwork

On the crown side, the case was enriched with screwed bumpers acting as crown protections. At only 42 grams and with a water resistance of 50 meters, the Bianchet Carbon Tourbillon B1.618 Openwork is destined for an active life. The watch is offered with a natural rubber strap with a titanium folding clasp that sustains the sporty intentions.

Bianchet Carbon Tourbillon B1.618 Openwork

Exemplify the golden ratio with an openwork design

The Carbon Tourbillon B1.618 Openwork received its name from simply expressing the values that define it: a tourbillon placed in an open design bridges following the 1.618 mathematical ratio. Additional decorative bridges, following the right curvature, are used as support for the hour doted indexes. An inner bezel register was printed with the rail track used by minutes.

  • 1.618
  • 1.618

The open-work design reveals the skeletonised main barrel under the top bridge. The Bianchet name and logo are placed on the upper side of the dial. For this particular model was used a combination of baton-shaped hour and minute hands with orange luminescent inserts.

  • Bianchet Carbon Tourbillon B1.618 Openwork
  • Bianchet Carbon Tourbillon B1.618 Openwork
  • Bianchet Carbon Tourbillon B1.618 Openwork

The lower side of the Bianchet Carbon Tourbillon B1.618 Openwork dial is dedicated to the tourbillon. An engraved titanium disc surrounds the hand-finished antimagnetic tourbillon cage to display the running seconds. The most impressive detail of this construction is the immense shock resistance – 6000 G.

Bianchet Carbon Tourbillon B1.618 Openwork

Unexpected charm

As with anything related to nature and its balance, the Calibre B1.618‘s construction will have a certain naturalness given by the implementation of the golden ratio in its design. Its charm comes as a natural consequence of the human eye being drawn to nature and to perfection. But this was not enough for the independent brand that took the difficult task of using titanium as the main material for its movement. The hardness of the metal makes it a rare choice for a watch movement since the decoration process is painstakingly slow (time and resources-consuming). Despite that, the watch is showcasing a series of well-decorated surfaces: Sand-blasting, circular-graining, and satin-brushing with a black DLC coating on the plates and bridges.

Bianchet Carbon Tourbillon B1.618 Openwork

Final notes

When I met the Bianchet Carbon Orange Tourbillon B1.618 Openwork during GWD 2022, I took the chance to study it, even more, and to see if the emotions created by the brand a year before still apply. It was just like meeting a person you rarely met but really enjoy his/hers presence. I was able to dive into emotions by taking the watches into my hands, and feeling the curvature and the unusual surface while my eyes enjoyed the spectacular spark of titanium particles in the sun. I did not find the mix of curves of the open-work movement as strange as the first time but pleasant, almost like it was natural to be in this way.

It made me understand, that like many other things in life, this could be an acquired taste. Some will find them as gorgeous as they really are from the first look. While I regret the closed-mindedness of the first encounter almost four years ago, now I am fully attracted by the complexity of the materials (the titanium/forged carbon combo is crazy beautiful), the apparent chaos of the 1.618 used almost obsessive in the watch creation.

What was never in discussion is the overall spectacularity of these tourbillon watches and their exceptional feel on the wrist. Their lightness and their openwork design were something that attracted me – the reason for our first encounter a few years back. While some might consider the finishing as not enough, the offering is justified by the price. So I am happy I took the time to understand them to their full potential.

Bianchet Carbon Tourbillon B1.618 Openwork

Bianchet Carbon Orange Tourbillon B1.618 Openwork Technical Specifications


  • Shock resistance: 6000 G
  • Water resistance: 50 meters (5 ATM)
  • Weight: 42g
  • Swiss made: Imagined, crafted and hand-finished in Switzerland
  • Warranty: 5 years

Movement – Calibre B1.618

  • Materials: Main plate, bridges and tourbillon cage in Grade 5 titanium
  • Tourbillon:
    • 60-seconds, hand-wound, 6 positions
    • Antimagnetic tourbillon cage
    • Variable inertia balance wheel
  • Frequency 3 Hz – 21,600 vph
  • Precision: -4+4 sec/day
  • Lubricants enriched with diamond nanoparticles to reduce friction
  • Finishes:
    • Sand-blasted,
    • circular-grained,
    • satin-brushed titanium plates and bridges with a black DLC coating,
    • hand-finished titanium tourbillon cage


  • Materials: Titanium-Dust-Infused Carbon and natural vulcanised rubber
  • Crown: Grade 5 Titanium
  • Crystal: Sapphire crystal with antireflective coating, case front and case back
  • Dimensions: 43 x 50 x 13 mm


  • Natural vulcanised rubber
  • Grade 5 Titanium folding clasp
  • Available in orange and black

Int’l retail price

  • CHF 55,000 CHF / EUR 55’000 (excluding taxes) / USD 60’500 (excl taxes)
  • Limited Series of 21 pieces

Bianchet, the genesis.
The genesis of Bianchet dates back to 2017 – Rodolfo Festa Bianchet is a successful fintech entrepreneur and the CEO of Riflexo, a software firm based in Turin that developed the first online trading application for mobile phones: Trade Interceptor. Inside the app, the TrendRisk engine analyses the psychology of the markets to detect and infer trends. The brains behind TrendRisk: Rodolfo Festa Bianchet, who based all the development work on the Golden Ratio 1.618 and the Fibonacci sequence.
His wife, Emmanuelle Festa Bianchet, was born to a French family of artists and musicians in Rome. As a pianist, she attended the conservatory, she is also an accomplished painter and sculptor, exhibiting in art galleries, her work as an artist was deeply influenced by the concept of harmony and its connection with the world of music and visual arts. She has always been fascinated by the universal beauty that radiates from the Golden Ratio of 1.618 and the Fibonacci sequence. This is something that both Bianchet founders have in common, and why they have chosen to build the brand’s aesthetic expression.Upon selling their software firm to a US company, they began to map out a project around what they both deeply loved, and where they could find and express themselves fully – their passion for watchmaking. Bianchet was born from this shared idea of creating something beautiful, anchored in reality and connected with the divine ratio, with eternity, something that will always remain.

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