Not all images were able to load for printing. Please close the print window and try again. The Zenith G.F.J. Revives the Legendary Calibre 135 (Incl. Video)
A new life for the legendary Zenith observatory Chronometer movement.
On the occasion of its 160th anniversary, Zenith celebrates its legacy in the field of precision watchmaking, bringing back to life the venerable calibre 135, the most awarded movement from the golden age of observatory chronometer competitions. In 2022, Zenith released an exclusive limited edition of 10 watches, powered by vintage 135-O movements, restored and decorated by Kari Voutilainen… and it was met with considerable interest by the watch community. What we get today is a recreation of this movement and a new collection, named G.F.J. – after the initials of the brand’s founder Georges Favre-Jacot. Here’s everything you need to know about this beautiful 39.5mm platinum three-hand chronometer.
Presented in 1948, the calibre 135 was specifically developed to meet the norms of the Neuchâtel Observatory competitions. Back then, and as can be seen with countless ads from that period, these were extremely important events with huge potential marketing benefits… The calibre 135 was created by Ephrem Jobin. At 30mm, its diameter was the maximum dimension to enter the wristwatch category competition. Its design was based on the idea of having an extremely large balance wheel to enhance precision and rate stability, and a large barrel to deliver consistent power to the regulator. This required a specific movement architecture with in particular an off-set minute wheel to free space. Beating at 18,000 vibrations/hour, the balance was fitted with a Breguet overcoil spring and a swan-neck regulator for optimal adjustment.
Some 11,000 units of the calibre 135 were produced from 1949 to 1962 in two distinct versions: a commercial variant (calibre 135) and an O iteration (135-O) created exclusively for observatory chronometry trials. The latter were meticulously prepared and regulated by the elite of Zenith watchmakers, the renowned Zenith chronométriers Charles Fleck and René Gygax. The Calibre 135-O received over 230 chronometry prizes which remains a record in the history of watchmaking. It also set another exceptional record with five consecutive first prizes (1950 to 1954) in the wristwatch category at the Neuchâtel Observatory. More on the topic in this in-depth article.
The Rebirth of the Calibre 135
There is this tendency to believe that watches were better before, that watchmakers of the past knew better how to make things the right way. Well, if respect for traditions is at the core of mechanical watchmaking today (as it should), modern technology enables significant improvements. In this context, the new G.F.J. Calibre 135 uses the architecture of his ancestor. At first glance, the new movement looks like a 1-to-1 reproduction as anyone could have hoped for; its layout is almost identical with its large barrel and its oversized balance wheel that features regulation screws, a Breguet overcoil and Charles Fleck’s characteristic double arrow-shaped regulator for fine adjustment. But there is more than meets the eye. The caliber 135 has been entirely re-engineered, integrating modern solutions or materials wherever possible.
First, the power reverse has been beefed up from 40 hours to 72 hours. This was made possible by the use of a new barrel spring (using Générale Ressorts’ Bioflex alloy). The new going train features an optimized toothing geometry for enhanced efficiency. The balance wheel still brats at a 2.5Hz frequency (18,000 vibrations per hour) but its inertia has been slightly reduced. Rubies have been added where necessary for improved efficiency, with a jewel count now at 22. Another important improvement, the movement now hacks when pulling the crown – allowing for precise time setting. The new Calibre 135 is, as you’d expect, chronometer-rated and is regulated to be precise to +/-2 seconds per day (the same as a Rolex Superlative Chronometer) and their precision is officially certified by the COSC.
The shock resistance has been improved too as the balance staff is now protected by spring-mounted jewel settings. The way the movement and dial are secured within its case have been upgraded for greater stability and protection. The material for the bridges is also a new modern brass alloy, allowing in particular for a more refined decoration, for instance for the added inward angles. The bridges stand out with their “brick” guilloche finishing, inspired by the facade of red and white-painted bricks of the Zenith Manufacture in Le Locle. The barrel features circular satin finish and the crown wheel is mirror-polished.
A nod to the era of the Calibre 135, the Zenith G.F.J. comes in an elegant 39mm platinum round case with a box sapphire crystal, a stepped bezel and curved stepped lugs. The notched crown is emblazoned with the G.F.J. initials. Its blue dial is a three-part construction; the outer ring features a “brick” guilloche pattern, facetted gold hour markers and a “pearl” minute track. The central part is a deep blue Lapis Lazuli with gold-coloured pyrite flecks. Last, indicating the passing seconds, the oversized subdial at 6 o’clock is in mother-of-pearl.
The Zenith G.F.J comes with 3 different straps: a dark blue alligator leather strap with a platinum pin buckle, a black calfskin leather and a blue Saffiano calfskin leather. A platinum bracelet with double folding clasp is also available upon request. It is released in an exclusive limited edition of 160 pieces. It can be purchased as an anniversary set with the 3 blue ceramic chronographs released on the occasion of the 160th anniversary. The price is set at EUR 52,900.
For more information, please visit www.zenith-watches.com.
