Zenith has presented the latest iteration of its iconic El Primero model, one of the most important chronographs in the history of watchmaking. As its name indicates, the latest model dubbed Lightweight features significantly reduced weight and it utilizes modern, durable and resistant materials in its construction. While the movement is made from titanium and silicone, the case is crafted from carbon nano-fibers and ceramized aluminum. Both titanium movement and carbon body are used in an El Primero for the first time. The new timepiece by Zenith is equipped with the same set of features as Striking 10th timepiece which debuted three years ago. Undoubtedly, the most notable of them is the “jumping seconds” function that allows precision display for its chronograph with the accuracy of within 1/10th of a second (El Primero still holds the title of the most precise mass-produced chronograph ever). The newest watch by the Swiss brand utilizes the traditional El Primero color scheme for the chrono counters on its skeletonized dial, and is issued in a limited edition which consists of 100 pieces, each available at the price of $22,000.

Zenith El Primero Lightweight Limited Edition Watch
A Horological Legend – El Primero Chronograph
El Primero is surely a legendary watch by Zenith. It was one of the first automatic chronographs when it appeared back in 1969. It is still uncertain (and as it seems it will probably remain so) whether it was actually the first watch that included the self-winding system and a chronograph, but we can say without any hesitation that it was the premier one that ran on the high frequency of 10 beats per second (36,000 vph). As it has been said, this is exactly the trait that makes the initial El Primero and all its later iterations the most accurate mass-produced automatic chronograph ever. During the course of years, the legendary movement was coupled with several other demanding complications and about three years ago, Zenith came up with El Primero Striking 10th piece. This watch punctuated its precision by incorporating a changed display for its chrono feature. In this model, the central chronograph sweeping second makes ten jumps per second and completes a full revolution every ten seconds, thus enabling the precision reading of the timed interval within a tenth of a second. This meant that the mechanism required an additional energy which is why Zenith used a double chronograph wheel made of silicone. Both of these characteristics – a precise “jumping seconds” chrono display and a silicone double chronograph wheel are once again used in the latest El Primero which Zenith dubbed Lightweight.
Reducing the Weight
The very name of the new model by the Le Locle based company suggests the general intention of the brand’s designers – the plan was to reduce the weight of the watch as much as it was possible. This was certainly quite of a challenge since the watch needed to remain as sturdy and reliable as its predecessor Striking 10th (as well as all of the other El Primeros) despite its diminished weight. In order to make it work, Zenith was forced to use high-tech materials which have all the qualities that the watchmaker needed. The whole process started with equipping the beating heart of the watch, its movement, with the necessary light components. Its mainplate and bridges (balance bridge, barrel bridge, chronograph bridge, pallete bridge and palette-wheel bridge) were made from titanium because of this. As a matter of fact, this newcomer is the first El Primero with the movement made of the material). Moreover, the silicon double chrono wheel used in Striking 10th was supplemented with a lever and escape-wheel made from the same material to further reduced the weight and enhance the properties. The end result is a caliber whose weight is reduced by a quarter – weighing just 15.45 grams, substantially less than a regular El Primero which weighs 21.1 grams.

Zenith El Primero Lightweight Limited Edition Case Back Watch
When speaking about the movement of the watch, one should note that the exact name of the caliber is El Primero 4052 W. It is a flyback chronograph movement with 31 jewels and the total of 334 components. The movement is 13 ¼ lignes (30 mm) wide, 6.6 mm thick and supplied with an automatic winding system and a power reserve which lasts for 50 hours. Just like all El Primeros, caliber 4052W has the frequency of 5 Hz. To make it more aesthetically appealing, Zenith decorated its oscillating weigh with Cotes de Geneve motif.
Bigger yet Lighter
The desire to make the watch as light as possible is likewise reflected in the choice of material for its housing, despite the fact that El Primero Lightweight is actually 3 mm wider than Striking 10th (45 mm compared to 42 mm). By constructing the round case from carbon which has a black color and a chequered motif, Zenith made the model appear sportier and enhanced its technical prowess. Carbon is coupled with ceramised aluminum which was utilized for the inner structure of the housing. This high-tech material has excellent features; it is very light and much tougher than the traditional materials. Unlike the common 316L steel whose toughness measures to 160-200 Vickers, ceramised aluminum’s strength is amazing 1,800 Vickers. Other efforts towards minimizing the weight of the case are the incorporations of titanium push-pieces and skeletonized lugs. For the crystal on the front and the transparent back of the watch, Zenith used sapphire (at the front side, the glass is cambered and with anti-reflective coating on both inner and outer side). As far as the water resistance is concerned, it measures to quite respectable 100 meters.
Old Motifs Reinterpreted
The face of new Zenith El Primero Lightweight which resembles a dashboard of a race car is a reinterpretation of some of the recognizable El Primero motifs – namely, the use of a traditional light gray, blue and anthracite counters which were present on the original El Primero from 1969. Moreover, the new watch also possesses a red central sweeping hand, though there is a slight distinction since the latest El Primero has a star shaped counterweight on it. Naturally, there are quite a few new elements visible on its face and the first one that pops up on mind is the fact that it is skeletonized to enable the view on the caliber from the front side too (the diameter of the opening is 38 mm). El Primero Lightweight likewise has a redesigned disc-type date display which was lightened and made with partially exposed date wheel. Situated at the very bottom of the dial, the disc includes pierced numerals. Once the appropriate number moves to the six o’clock position where it is used to indicate current date, it stands on a red background, thus appearing to change color, which looks quite neat. Otherwise, it is noteworthy to say that both hollowed hands and the hour markers on the flange are faceted, rhodium-treated and coated with Superluminova SLN C1 coating for improved legibility.
In accordance with the general featherweight theme, new Zenith El Primero (with the reference number 10.2260.4052W/98.RS73) has a neat black strap made from rubber and another futuristic material called Nomex which locks with a black triple folding clasp. The newcomer by the Le Locle watchmaker is issued in a limited series of 100 copies with the place in the series indicated on the bottom of the case-back.