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This column, narrated from an engineer's perspective on mechanical watches, is the 56th installment.
"What is Cal.4030, the Daytona's last movement based on another company's design?"
This is the topic we will be discussing.
Rolex's "Daytona" is now one of the most famous chronographs in the world. Its overwhelming popularity and premium prices in the secondary market are well known. Within the history of the Daytona, an undeniable fact is the legendary movement "El Primero," based on a Zenith movement from around 1988 to 2000, which has left its mark on watchmaking history.
This time, we will explain this "miraculous relationship" born between Zenith and Rolex from an engineer's perspective, in an easy-to-understand way.
The Race for the World's First Automatic Chronograph
*SEIKO Cal.6139
The story begins in 1969. At that time, the watch industry was in a development race for the "world's first automatic chronograph."
The contenders were:
- Zenith
- Heuer-Breitling-Buren (Chronomatic)
- Seiko
These three camps.
Zenith, outpacing its rivals, completed the "El Primero," which means "the first" or "the number one" in Spanish.
What was so great about the El Primero?
Its most significant feature was its high beat rate of 36,000 vibrations per hour.
Because it ticked more precisely than regular watches, it offered significant advantages:
- Easier to achieve accuracy
- Smooth chronograph measurement
- Capable of measuring to 1/10th of a second
It was also an unprecedented "all-in-one movement" that combined automatic winding with a horizontal clutch chronograph. However, in the 1970s, the quartz watch boom devastated the mechanical watch market.
Zenith also faced a financial crisis, and there was talk of "discarding mechanical movement manufacturing equipment." But a legendary episode emerged here. Zenith watchmaker Charles Vermot, believing that "the era of mechanical watches will return someday," hid the El Primero's blueprints in the factory attic.
Though, personally, I think this story might have been embellished later. (laughs) Either way, having a compelling backstory is definitely a factor in its popularity.
Rolex, the Automatic Chronograph Problem
*ROLEX Cal.727
In the late 1980s, Rolex faced a major challenge.
At the time, the Daytona was hand-wound, but the era had completely shifted to automatic winding. That's when Rolex set its sights on Zenith's "El Primero." However, Rolex didn't simply "borrow" it. Rather, it's more accurate to say they thoroughly "Rolex-ified" it.
Significant Modifications by Rolex
The El Primero, modified by Rolex, was named "Cal.4030," and its internals were significantly altered, including changing the oscillation from 36,000 vph to 28,800 vph.
The reasons were:
- Improved durability
- Improved maintainability
- Improved oil longevity
In other words, Rolex prioritized "practicality characteristic of Rolex." While some may view this change in oscillation frequency negatively, I believe from an engineer's perspective that prioritizing durability over a visually appealing number was the correct decision.
Many parts were changed in addition to the oscillation frequency.
- Balance wheel
- Escapement
- Automatic winding mechanism
These were adapted to Rolex specifications. While Zenith focused on "speed and technology," Rolex prioritized "reliability for daily use." The difference in philosophies is quite interesting.
The 5-digit reference Daytonas, such as the Ref.16520(SS), are known as "El Primero Daytonas" in Japan and "DAYTONA “ZENITH MOVEMENT”" overseas. Personally, I feel this is half right and half wrong. It is true that Cal.4030 shares its basic structure with the El Primero.
However, as mentioned earlier, Rolex's unique modifications are extensive, and I believe that the actual manufacturing was carried out in Rolex's factories.
Summary
How was it?
In the world of watches, brands are often portrayed as rivals. But in reality, technology has been shared and evolved. The relationship between the El Primero and the Daytona is an iconic example of this.
If Rolex hadn't chosen Zenith as a partner at that time, the current Daytona legend might not exist. When you think about it that way, the "El Primero Daytona" might be a watch that carries the very history of watchmaking on its wrist.
I hope this article has provided you with useful information and sparked your interest in luxury watches! If you have any questions, please feel free to ask us directly, and we will be happy to assist you. We look forward to your visit and inquiries.
Stay tuned for the next installment! See you then!
