written by:
the eclecticum


collectors, Novelty 2021, watches, Zenith

Zenith ´Chronomaster Sport` – a new dress and the El Primero Cal. 3600: updates with benefits…

The venerable El Primero gets a first substantial upgrade (Cal. 3600) in 5 decades: 1/10 of a second, more autonomy, conventional crown positions, and revised chrono mechanics, clothed in a new old dress – ´Chronomaster Sport`

The El Primero movement is something like the ‘raison d’être’ for the Zenith: without it, the manufacture would very likely not exist anymore. Without it, however, the entire watch industry would look different even.

The movement was so iconic and proved future-proof that Zenith largely refrained from chaining ‘the winning team’. That was until today, and now the brand presents a carefully upgraded version, called Cal. 3600, with some significant improvements, and celebrates this with an equally carefully revised Chronomaster Sport collection:

Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600(The new Cal. Zenith El Primero 3600)

New old movement – and a legend:

While we normally would cover the watch first and the movement second, we take the freedom to reverse sequence owing to the prominent position the El Primero movement enjoys in the history of the chronograph.

Side note: In the late 1960 years, the El Primero Cal. 3019PHC (its name back then) was one of the three movements that raced for the crown of the ‘first automatic chronograph movement’ ever, a race it fought together with the Chronomatic, better known as Cal. 11, developed by a joint venture of Heuer, Breitling, Buren and Dubois-Depraz, and Seiko’s Cal. 6139:

First automatic Chronographs Zenith 400 Buren Cal. 11 Seiko 6139(from left: Zenith El Primero, Heuer/Breitling/Buren/Dubois-Depraz Cal. 11, and Seiko Cal. 6139)

All of them were decidedly different in approach, the Zenith a classically integrated column wheel movement with a high beat escapement, the Cal. 11 a modular cam/lever operated one with micro-rotor, and the Seiko finally integrated and with column wheel as well, but also with a vertical clutch and Seiko’s efficient ‘Magic Lever’ winding.

Who finally was ‘the first’ is hotly debated until today, and depends on how one defines ‘fulfilment’: Zenith was the first to announce (in January 1969) but the last to deliver, the Cal. 11, announced in March, was the first to be delivered worldwide (August 1969), while Seiko also presented in March but delivered already two months later, but only in Japan.

Nevertheless, it was the El Primero which made the longest lasting impression – until today.

But this was not entirely foreseen at launch nor was it guaranteed in its history: just two years after its launch, Zenith was sold to an eponymous US consortium which eventually decided to abandon mechanical timepieces, and ordered machines, parts and technical files to be destroyed. Zenith watchmaker Charles Vermot, convinced that this would be a fatal mistake, secretly tucked away everything that reminded on the El Primero in an attic of the manufacture.

Zenith manufacture Le Locle attic El Primero Charles Vermot(The attic where Charles Vermot saved the El Primero. Still preserved until today)

Years later, in the early 1980s, Pierre-Alain Blum of Ebel inquired at Zenith on the possibility of obtaining some El Primero movements. When the management was about to decline the request, convinced that everything was destroyed, Charles Vermot raised his voice and said: ‘there is something I want to show you…’

The rest is legend, El Primero was one of the pacemakers in the revitalisation of classical watchmaking and the Swiss watch industry. Rolex used it for the first version of the Daytona chronograph (they had a dedicated workshop within Zenith for the requested modifications) as did many other brands, including – ironically, TAG Heuer.

The El Primero remains the cornerstone of Zenith to this day, as has seen numerous complications built upon it, such as tourbillons or even minute repeaters.

Besides complications added to different aesthetic versions realised, Zenith themselves never really touched the fundamentals – that is until now: With today’s presentation of the new El Primero Cal. 3600 the future of the legendary movement unfolds:

Zenith El Primero 3600 automatic chronograph movement

On first view, everything seems to be the same again. And at least of surface it is, since Zenith decided to do what true watchmakers at heart do: improve on the substance!

Perhaps the view is a bit clearer when the rotor is removed:

Zenith El Primero 400 3600 automatic chronograph movement

The new Cal. 3600 differs from the older Cal. 400 as follow:

  1. capable of recording 1/10th of a second
  2. modified subdial layout: chrono-sec (3 o’clock), chrono-min (6 o’clock), permanent-sec (9 o’clock) vs chrono-min (3 o’clock), chrono-hours (6 o’clock), permanent-sec (9 o’clock)
  3. permanent minutes counter for up to 60min
  4. larger column wheel
  5. reworked horizontal clutch gearing to reduce the activation jump
  6. increased power reserve of 60h thanks to optimised energy flow
  7. crown portions now like with most movements (pos 0 – winding, pos 1 – date setting, pos 2 – time setting (& stop seconds)
  8. hacking seconds
  9. integrated modularity to facilitate further variants (complications, display options)
  10. less parts (screws, jewels, studs)
  11. streamlined assembly

Everything else stays the same, and this we guess that for most these are very welcome modifications, particularly as the characteristic layout of the El Primero is mostly kept. As we wrote in the beginning, there are benefits – for the customer, the connoisseur and of course the company as well.

New old dress:
The new Chronomaster Sport Collection

To give the mechanical upgrade more visibility, Zenith opted to present it together with an equally upgraded collection: the Chronomaster Sport Collection:

Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600

The new collection has – like the El Primero itself – historical roots within Zenith: The De Luca collection, presented in 1988 upon request of the brand’s Italian import agent. It was the first ‘modern’ Zenith, and an unexpected commercial success – according the reference book of Manfred Rössler, about 8750 De Lucas watches have been made. De Luca Zeniths are meanwhile sought-after collector’s pieces:

Zenith De Luca automatic chronograph El Primero Cal. 400(A Zenith De Luca from 1998. This watch has a rotating bezel, but those with fixed ones, e.g. with tachymeter scale, existed as well)

Originally, Zenith planned to present the Cal. 3600 for the 50th anniversary of the El Primero movement two years ago. Prototypes were ready, and Zenith even showed a watch, without much fanfare, as part of an anniversary set:

Zenith 50th anniversary set automatic chronograph El Primero Cal. 3600

The watch already anticipated much of the final one, but there was still some way to go (e.g., this was still based on the Striking 10th version of the original El Primero (note subdials!), and we are glad Zenith did take their time:

Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600

Housed in a 41mm stainless steel case, the Chronomaster Sport is a quintessential Zenith – an everyday companion, precise, robust and reliable. It is not a flashy watch, but one which shows that Zenith indeed does care.

The choice of the details exemplifies that Zenith has set its focus again on watchmaking, something that was not always obvious to us, to say the least: In the classic tri-compax arrangement of subdials, we find a central 1/10th of a second counter, the chronograph second at 3 and the minutes at 6 o’clock, respectively, with a permanent seconds at 9. This at the same time familiar and usual.

Zenith Chronometer Sport automatic chronograph El Primero Cal. 3600(Design details of the new Zenith Chronometer Sport)

The subdials have only little overlap, and this in the correct order: the shorter interval cuts into the longer one (seconds into minutes). The chronograph function is also emphasised through colour, with the chrono subdials being more prominent (at least on the light dialed watch) and all chronograph hands sporting a red accent. Finally, all hands are nicely sized:

Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600

The scale of the 1/10th seconds counter is engraved on the black ceramic bezel: 

Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600

It is probably useful to observe the watch in action (first the chronograph, then the crown positions):

Zenith offers a second version, with a black dial – besides this we note: certeris paribus:

Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600

A display-back shows the new movement, in the meantime carefully and partly open worked to allow a better glimpse in its inner workings, a blued finish added to the column wheel, and the rotor carries a relief engraving:

Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600 Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600 Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600

Finally, there is a new steel bracelet with secure lock, which according to Zenith is also modelled after a vintage one Gay Frères made for the De Luca, as well as a textile-cum-rubber strap (which we have not seen yet).

Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600


The allure of a brutally honest wrist-companion

Let’s get one thing out of the way immediately: no one would sleep outside of a Zenith boutique or retailer to get one’s hand on the new Chronomaster Sport. That´s fine, a solid and classical ´luxury tool` comes to our mind – instead of being addicted to fashion or glamour – and for sure the watch is far from being a gadget only.

Yet it is an immensely attractive and significant watch, that just delivers what one would expect (but not often gets) from fine Swiss watchmaking today: loosely modelled after one of Zenith’s most iconic pieces, it slots nicely between the ubiquitous Valjoux 7750 powered watches (which are technically also a nice distance behind), and the finer, modern automatic chronographs from Blancpain (those Piguet-based chronographs are also used by Vacheron Constantin, Audemars Piguet, …), Czapek or Parmigiani.

On a finer granularity, the Chronomaster Sport further slots squarely between the likes of the OMEGA Speedmaster or the Breitling Navitimer one the one, and the Rolex Daytona on the other side, all iconic chronographs on their own right.

Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600

Design aside, all of them have their specific strengths and features, with probably the Speedmaster competing most fiercely: timekeeper-focussed (co-axial escapement, Master Chronometer) vs. chronograph-focussed (1/10th seconds counter, column wheel), manual vs. automatic – your choice! Especially since OMEGA now offers a real bang for the buck with the recent introduction of the Cal. 3861.

But the white elephant in the room is the Rolex Daytona – ‘the’ quintessential chronograph, and an icon far extending the realm of watches. There is a historical connection between the two, both are ‘sports chronographs’ with similar design codes, and both were at least for 12 years powered by the same El Primero (base) movement. Its guesswork but reasonable to assume that the Daytona would perhaps not have happened wouldn’t be there the El Primero, which allowed Rolex to keep a comparatively slim case. More like Zenith, Rolex has continuously improved their movements, but Zenith has closed that gap now.

Priced at about 30% above the Chronomaster, the stretch between the two watches is what we would call ‘manageable’ (provided one could mentally pass the 10k € barrier). But do you get 30% more? We have our doubts, based on features alone, but here individual preferences count.

What is less manageable is the availability, or the lack thereof, of the Rolex. This is a crucial impediment for the latter, an allure for some (probably not the ‘purist’ collector we have in mind…) and a practical advantage for the Zenith. But does this tip the scale, for a collector? These are ‘environmental factors’, and not those intrinsic to a given watch. Whether the Chronomaster is a replacement for a Daytona or only a distant second choice, that is your call, only.

Now, the fact that Zenith upgraded its most known and legendary movement is an important notion. The brand signals that it believes in its future, and this expressed in how they did it more so than in the fact that the El Primero has been updated at all: Zenith kept the key ingredients (36,000 A/h, column wheel, core architecture) and spent efforts where the movement needed it: there is the 1/10th of a second counter useful to substantiate the ‘El Primero’ moniker (we guess we all agree that your hand is less precise that this chronograph…), the 60min counter (yeah, no 30 min one!), the keyless works and with it the crown positions are now laid out exactly as most other watches, and it finally got a hacking function.

But one significant update is a bit hidden behind all these features: the movement has been made easier to assemble, and now also is designed such that additional functions can be better integrated.

You have to digest this: despite being more than 5 decades in production now, the original El Primero never really has been properly industrialised! With the Cal. 3600, Zenith has done this, and done in a way that much more is straightforward (comparatively!) to achieve. As we mentioned above, it offers benefits – serious ones.

Zenith Chronomaster Sport automatic chronograph El Primero Cal. 3600

The new Zenith Chronomaster Sport with the new Cal. 3600 is a significant step. It is a (luxury) mainstream watch for sure, but one done with measure and aplomb. It is an important watch which offers true watchmaking excellence at an attractive price point, and shows that even there real watchmaking, instead of ‘product development’ can and does take place (at times). Also, it should be of importance when we think about sales figures, because it will speak to quite a few people which are in the market for something solid that delivers and feels like a good investment – in the long run. Good news, as it is industrialized up to date.

It is therefore only fitting that Zenith chose the ‘Sport’ collection to take inspiration from the famous De Luca, which signalled that modern Zenith watches could be successful on their own right… now this we think cannot be coincidence!

the eclecticum


3 replies
  1. Arnaud
    Arnaud says:

    Great write-up for this great watch !
    If I may digress on a tiny detail here, it’s been now proven that Seiko started delivering its 6139 in May 1969 both for the Japanese and global market. The global design of the watches was finalized in August 68 and production of movement and parts started in October 68. The earliest completed watches we know of as of now are from January 69. I can only invite you to check Ryugo Sadat’s book « The history of Seiko 5 Sports Speed-Timer » 😉

    By the way, I really love your website and your content, keep up the good work, it’s truly captivating !

    • the eclecticum
      the eclecticum says:

      Dear Arnaud:

      fascinating information – the subject of the first automatic chronograph is never shy of new facets. Let alone the question of what defines ‘first’: press presentation, public launch or deliveries? Interesting though that at the Basel Fair in April 1969, Mr. Itiro Hattori, then President of Seiko, congratulated the Heuer team for the launch of the world’s first automatic chronograph.

      ‘the eclecticum’


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