Zenith Chronomaster Open

Zenith has spent quite a bit of time over the past few years streamlining its core collections, making sure every one of its watches offers something different, to a different set of customers. The Defy, for instance, has a hyper-modern design to reflect its cutting-edge high-frequency movement, while the flagship Chronomaster line now focuses exclusively on Zenith’s expertise in the chronograph category.

As part of this streamlining process, Zenith has entirely reworked the Zenith Chronomaster Open line over the past 16 months, centering it around the introduction of the El Primero caliber 3600, an updated version of the OG El Primero caliber 400 from 1969 that enables elapsed timekeeping functionality up to one-tenth of a second, in order to best take advantage of the El Primero’s famous operating frequency of 36,000 vph, or 5 Hz. The Chronomaster Sport debuted to massive commercial success – the steel models are on waitlist pretty much everywhere in the world right now – and it was soon followed by the vintage-inspired Chronomaster Original. The Chronomaster Revival models will remain enthusiast darlings that are now positioned slightly in the background of the collection, still running off the El Primero 400 for the time being (I assume for authenticity’s sake).
The final chapter of the new-look Chronomaster series is being released at Watches and Wonders 2022. Announced today, in Geneva, Zenith has officially reworked the Chronomaster Open, its mid-2000s flagship that features an exposed escapement rendered in “open heart” fashion, with a new case and dial design as well as the implementation of the caliber 3600. The previous 42mm option is now discontinued and has been wholly replaced by the new Chronomaster Open series, which is available in three options (two in stainless steel, with either a silver or black dial; one in rose gold, with a silver dial) to start.
Beyond the new caliber, Zenith has updated the Zenith Chronomaster Open series with a brand-new case design that measures 39.5mm × 13.1mm, with a lug-to-lug of 45.2mm that should help it wear smaller than even the Chronomaster Original. The overall look and feel of the case is close to the Chronomaster Sport, with a similar crown, pump pushers, caseband, and lug combination, but without the visual and tactile heft of the ceramic bezel.

The dial execution now consists of 16 total components and has been completely reworked compared to previous versions. It now features a hesalite window that exposes the entirety of the escapement, including the balance wheel, the silicon escape wheel, and the seconds wheel. The caliber 3600 was slightly reworked – now christened the El Primero caliber 3604 – primarily through the skeletonization of the escapement in order to expose the beating of the balance wheel and give a real-time, always-on display of the El Primero’s 10 beats per second. This is also the first time we’ve seen a no-date version of the caliber 3600 offered.
Compared to the perlage decoration found on previous El Primero movements used in the Zenith Chronomaster Open line, Zenith opted instead to finish the visible front-facing arms and bridges of the caliber 3604 with a three-dimensional, laser-engraved concentric azzurage pattern that better complements the finish of the “non-open” sub-dials that display elapsed hours and minutes, in grey and blue (those colors are, of course, a reference to the tri-color sub-dials on the original El Primero A386). Zenith also eschewed a frame for the dial opening, instead opting for chamfered edges for a less disruptive dial orientation.
The Zenith Chronomaster Open series has been in serial production at Zenith since it was revealed in 2003 under the hand of Thierry Nataf, the company’s frequently provocative leader from 2001 to 2009. While many of Nataf’s decisions haven’t stood the test of time, the Chronomaster Open has been a huge and remarkably resilient commercial success for Zenith in many of its key markets over the past two decades. The Grande ChronoMaster Open El Primero even walked away with the Men’s Watch Prize at the 2004 edition of the Grand Prix d’Horlogerie de Genève (GPHG), an award it shared with the Patek Philippe Gondolo Calendario 5135 G in a rare tie.

While a familiar face in many ways, the Zenith Chronomaster Open has been cleaned up in a way that keeps it in line with the Chronomaster collection’s aesthetic codes that were cemented by the success of last year’s Chronomaster Sport and Original lines. The dials are less crowded, the cases are more wearable across wrist sizes and genders, and the movement is more reflective of Zenith’s current capabilities.