An avant-garde sports model from ZENITH the El Primero Lightweight

Zenith EL Primero Lightweight in limited edition of 100 pieces

Zenith EL Primero Lightweight in limited edition of 100 pieces

Zenith focuses firmly on lightness, daring and innovation in an exclusive version of its El Primero Striking 10th chronograph featuring high-tech materials. Issued in a 100-piece limited edition, the El Primero Lightweight model teams a titanium and silicon movement with an ultra-sporty carbon case. It signals the dawn of a new era in the fabulous history of the legendary 
El Primero calibre.

The Zenith El Primero 3019 PHC movement dating from 1969

The Zenith El Primero 3019 PHC movement dating from 1969

At the time of its launch in 1969, the El Primero calibre overturned existing conventions by asserting itself as the first-ever automatic chronograph to boast an integrated construction. Also impressing observers by beating at the exceptional frequency of 10 vibrations per second (36,000 vibrations per hour), it is still the world’s most precise series-made chronograph calibre. Over the years, Zenith has steadily fine-tuned its legendary movement in order to optimise its precision, its reliability and its performance. The brand with the guiding star has also taken up the challenge of associating its high-frequency chronograph with other complications such as the tourbillon, the perpetual calendar and the split-second function. In 2010, Zenith reinvented the “jumping seconds” in presenting the El Primero Striking 10th. Equipped with a sweep seconds hand making ten jumps per second and a complete turn of the dial every ten seconds, this chronograph not only measures but also displays tenths of a second with extreme precision. To enhance the performance of this mechanism requiring a considerable amount of energy, the Manufacture from Le Locle notably fitted it with a double chronograph wheel in silicon, a material three and a half times lighter than classic alloys.

A featherweight engine

Zenith is now taking a new turn by unveiling a sportier and even more avant-garde version of the El Primero Striking 10th. The watchwords are lightness, performance and originality. Through combining technological innovation with creative daring, the engineers and watchmakers of the Manufacture were tasked with the mission of reducing the weight of the watch to an absolute minimum, yet without making any compromises on its precision, its sturdiness and its reliability – just as an engine designed for competition is optimised while bearing all these factors in mind. The sizeable feat began with the movement. Based on its latest research relating to new materials, Zenith chose titanium – a light and resistant metal widely used in aeronautics – to machine the main elements of the movements that are the heaviest parts of the watch when they are made in brass: namely the mainplate and five bridges (barrel bridge, balance bridge, pallet bridge, pallet-wheel bridge and chronograph bridge). The Manufacture has also maintained the silicon double chronograph wheel, while adding a lever and an escape-wheel made from the same high-tech, light, antimagnetic material that is harder than steel and guarantees excellent efficiency. The result is a one-quarter lighter engine weighing just 15.45 g (compared with 21.10 g for a similar classic movement).

Sleek, masculine bodywork

The 45mm carbon case and the El Primero 4052 W

The 45mm carbon case and the El Primero 4052 W

In terms of the watch exterior, the designers reworked and subtly enlarged to 45 mm the original 42 mm case of the El Primero Striking 10th, while also seeking to make it as light as possible on the wrist. The choice of carbon with its fine black colour and its “chequered” effect evoking the world of competitive racing fits the bill perfectly, while also reinforcing the technical and sporty look of the model. The inner structure of the case is made of ceramised aluminium, a cutting-edge material that is at once light, sturdy and hard (1800 Vickers, as against 160-200 for 316L steel). The two chronograph pushpieces are in titanium. The openworked lugs accentuate the aerodynamic profile of the watch and ensure a perfect flow into the integrated black rubber and high-performance Nomex synthetic fibre strap equipped with a triple folding clasp providing optimal security and comfort.

A stylish dashboard

The new El Primero Lightweight is also distinguished by its highly original dial featuring a dynamic reinterpretation of the collection’s design codes. Openworking the central part further enhanced the overall lightness-oriented effect while providing a clear view of the El Primero calibre (also visible through the transparent caseback). The disc-type date display has been lightened and reworked with pierced numerals standing out on a small red disc at 6 o’clock. The facetted hands have been hollowed as much as possible and then highlighted by a luminescent coating. The light grey, blue and anthracite colours recapture the three emblematic colours of the 1969 El Primero chronograph that have become iconic brand features. The red sweep seconds hand with its small Zenith star accurately measures feats to the nearest tenth of a second – just as on the dashboards of the greatest racing champions.

Sporty, contemporary and decidedly masculine by nature, the El Primero Lightweight model brings a distinctive touch to the Zenith collections, while powerfully confirming the innovative capacities and the creating daring cultivated by the Manufacture. With its avant-garde technology and its youthful, dynamic look, it shows that the El Primero calibre still has a bright future ahead of it and doubtless heralds new developments as the brand with the guiding star is gearing up to celebrate its 150th anniversary in 2015.

Technical Specifications

Exploded view of the Zenith El Primero 4052 W

Exploded view of the Zenith El Primero 4052 W

El Primero Lightweight

  • 1st EL PRIMERO CALIBRE IN TITANIUM (5.64 g lighter than a classic El Primero calibre, meaning a more than one-quarter reduction)
  • 1st automatic El Primero flyback chronograph displaying 10ths of a second
  • 1ST carbon case
  • Openworked dial
  • 100-piece limited edition

El Primero 4052 W, automatic
Calibre: 13 ¼ ‘’’ (diameter : 30 mm)
Thickness: 6.60 mm
Components: 334
Jewels: 31
Frequency: 36,000 VpH – (5 Hz)
Power reserve: min. 50 hours
Finishes: Oscillating weight with 
“Côtes de Genève” pattern
Titanium components: mainplate, barrel bridge, 
balance bridge, chronograph bridge, pallet bridge and pallet-wheel bridge

Hours and minutes in the centre
Small seconds at 9 o’clock
Date window at 6 o’clock
Chronograph with 1/10th second display:
– 60-minute counter at 6 o’clock
– 60-second counter at 3 o’clock
– I/10th second indication by the chronograph hand

Case, Dial and hands
Material: Carbon
Diameter: 45 mm
Opening diameter: 38.50 mm
Crystal: Cambered sapphire crystal glareproofed on both sides
Caseback: Transparent sapphire crystal
Water resistance: 10 ATM
Dial: Openworked with three coloured counters
Hour-markers: Rhodiumed, facetted and enhanced 
with Superluminova SLN C1
Hands : Rhodiumed, facetted and enhanced 
with Superluminova SLN C1

Nomex-coated black rubber strap and 
black triple folding clasp

As a graphic designer, I'm fascinated by the crossroads between technology and aesthetics. Horology is one of these crafts, where art and engineering come together to produce mechanical wonders that grace the eye. WatchPaper was born from the desire to create an online tool where I can share my passion for watches.