You might have heard of the El Primero. It's ZENITH's legendary high-frequency movement, and one of the first automatic chronograph calibres in watchmaking history.
It's been over 57 years, and yet much of ZENITH's identity still revolves around it, which never fails to blow our minds. When was the last time you heard of a calibre from the '60s still being relevant today? The El Primero is what paved the way for functions like pushers, subdials, and tenth-of-a-second precision to become such a common sight.
So when the new Chronomaster Solo Sport was revealed at Geneva Watch Days 2026 as a clean, three-hand watch with none of its signature stopwatch functions, it left a few people scratching their heads. How can the grandfather of chronographs power a watch without one?
Believe it or not, we actually think it's a love letter to the El Primero movement itself. By subverting expectations and shaving off the chronograph functions that the movement powers, it draws attention back to the El Primero.
What made the original movement so remarkable wasn't just that it unlocked the door to all these complications. It was also that it ticked at 36,000 vibrations per hour (5 Hz), roughly double the standard beat rate of the era, while keeping its dimensions svelte and slim. That high-frequency escapement was what let it measure to a tenth of a second, while giving its seconds hand that smooth, satisfying swoop.
With the chronograph gone, ZENITH is able to make the Chronomaster more accessible, offering the El Primero's high-frequency movement at a lower price. It's a major plus for anyone who's been vying to get their hands on the legendary movement. But on top of that, it also means the Maison can now zero in on making the high-frequency character the main focus.
This is where the design gets clever. The dial's ceramic surface is built around a repeated 45-degree “Z” motif, meant to visually echo the vibration of the movement underneath. The “Z” motif extends to the seconds hand counterweight, serving as a constant reminder of what gives it that smooth movement. Even the minute track features a “shark tooth” pattern, ZENITH's attempt at visualising what a 5 Hz pulse might actually look like.
Under the hood sits the El Primero 3620, derived from the 3600 chronograph movement but stripped down to hours, minutes, a central seconds hand, and a date display. With a silicon escapement, a stop-second mechanism, and a bi-directional winding system with a star-shaped rotor, it delivers 60 hours of power reserve and up to 200 metres of water resistance. This will, of course, all be available for your viewing pleasure on the caseback, which features a new oscillating weight with a star-shaped, openworked design.
The Chronomaster Solo Sport is also furnished with ZENITH's new ZENCLASP folding clasp, which was presented at Watches and Wonders 2026. Three years of development and research in the lab mean users now have the flexibility to resize the bracelet directly on the wrist, without tools, by up to 10 mm.
Measuring a versatile 40 mm, the watch comes in four flavours: a white dial with a classic black unidirectional ceramic bezel, a black dial with the same black bezel, a brown dial with a matching brown bezel, and a simplified black-dial-black-bezel variation minus the date display.
The Chronomaster Solo Sport is now available through ZENITH boutiques, online, and authorised retailers worldwide.
