Rolex Cosmograph Daytona "Zenith" 16520 automatic 40 mm Full Set 1996

Where it all begins

Highlight of the first speed records, Daytona Beach in Florida owes its fame to one man: Sir Malcom Campbell. An English-born racing driver, he devoted a large part of his life to motor sport, and distinguished himself by his numerous records, notably at the wheel of his car nicknamed "Bluebird", with which he set a new record at over 396 km/h. It was in this context of pushing back the frontiers of the possible that Sir Malcolm Campbell came to the attention of Hans Wilsdorf, founder of Rolex, and became an ambassador for the brand. In 1962 the brand would become the official sponsor of the Daytona race.

The reference 116520

The late 80s saw a stylistic revolution at Rolex with the arrival of the first 5-digit references! The "Submariner" was transformed from a true "toolwatch" into a luxury diver's watch with white gold-circled hour-markers, the iconic "Explorer" ref. 1016 left the catalog after 30 years of production to make way for a watch with a shiny dial and applied hour-markers to give it a more modern look, and this design philosophy was applied to many other models.

In 1988, it was the turn of the "Cosmograph Daytona" to enter a new era! For its 25th anniversary, the brand with the crown launched reference 16520, an entirely new watch! This is the first "Daytona" to feature a self-winding movement and sapphire crystal. From an aesthetic point of view, major changes take place: the case is thus increased from 37 to 40 mm in diameter, the dial takes on a new, more masculine look with arrow-shaped indexes, softened sub-dials with inverted color contours to contrast with a more conservative design.

On this example made in 1996, we find a sublime white tritium dial known as "MK5", with its "Oyster" type bracelet reference: 78390 with polished finish in the center and satin finish on the two outer links equipped with the "Oysterlock" clasp. Last but not least, the iconic "MK3" bezel features a steel tachometric scale, graduated from 400 km/h, and a "240" indication instead of 250 and 225. This mid-1990s model is much more chic and luxurious than the first versions.

The 4030 caliber and its history with Zenith

To revolutionize its iconic model, Rolex wanted to enliven it with an automatic movement. Indeed, Cosmograph Daytona customers, although satisfied with the Valjoux 72 that powered their watches, wanted the arrival of an automatic caliber. Rolex therefore undertook external sourcing for this new chronograph caliber. Only the "El Primero" met the space-saving characteristics sought by the brand with the crown.

As Rolex always does with its outsourced blanks, the caliber 4030 was extensively modified to meet Rolex's performance requirements. As such, it required no less than four years of R&D in order to carry out a major adaptation by replacing more than half of the parts, with the aim of improving the performance of this "engine".

Firstly, to minimize component wear, the oscillation frequency was reduced from 36,000 to 28,800 A/h. Secondly, the date function has been removed from the original base. Thirdly, the escapement system has been modified with a Glucydur spring balance and a Breguet balance spring, replacing the original flat balance spring.

For the record, Rolex will invest quite heavily in Zenith's production capacity and stand surety for the banks so that the brand can relaunch production of its mythical caliber. It took two years, but in the end Rolex saved Zenith from bankruptcy. Satisfied that the company could meet its needs, Rolex awarded Zenith the ten-year contract.

This caliber would endure from 1988 to 2000, before Rolex itself manufactured the movement in its entirety by developing its own manufacture movement with caliber 4130, which would equip reference 116520 from the 2000s.

The Package

This "Cosmograph Daytona Zenith" reference 16520 is in excellent condition and will be delivered to you Full Set. This therefore includes the original case, the Rolex document holder with its COSC certificate and its warranty dated 1997. The set also includes the calendar and the period reference tag. This watch is entirely original and has a homogeneous patina. It has been authenticated by our ROLEX-approved watchmaker and is covered by the Lepage Vintage 1-year warranty.

Technical data :

• Reference : 16520
• Year of manufacture : 1996
• Serial number : T62XXXX
• Bracelet : Oyster 78390
• Endlink : 503B
• Claps code : V10
• Movement : 4030
• MK5 Dial
• Excellent condition