Rolex Cosmograph Daytona SS 116520

Here is the Rolex Cosmograph Daytona in stainless steel with black dial model number 116520. I don't care about the whole inflated street price fiasco of this watch, what I'm interested in is the fact that this is one of the most beautiful chronographs I have seen and it contains Rolex's first in-house chronograph movement designed with traditional Rolex traits of durability and precision. When Rolex went about to create this new movement, they incorporated the input from their service department and the result is a chronograph with a minimal amount of moving parts and a design that allows ease of service to ensure the longevity and ruggedness of the movement. Furthermore, the 4130 chronograph movement contains standard Rolex features like the Breguet overcoil, microstella adjustment, balance bridge, large diameter balance wheel and proprietory balance pivot. My knowledge about the movement is very limited; however, the calibre 4130 utilizes the vertical clutch braking system to allow for a smooth engagement of the chronograph and the elegant column wheel to guide the functions of the chronograph.

Something new in the calibre 4130 is Rolex's very own balance spring known as Parachrome Blue which is an alloy consisting of Niobium and Zirconium. The Nivarox balance spring was designed to withstand the negative effects of change in temperature to timekeeping, but it is susceptible to magnetism and shock. The Parachrome Blue is ten times more shock resistant than normal balance springs and completely unaffected by magnetic fields in addition to being highly resistant to temperature change. This is a very important breakthrough in watch-making and what is surprising is the fact that the Parachrome Blue has been utilized since 2000 when the first caliber 4130 Daytona's rolled off the production line.

Another interesting aspect of this chronograph design is that the movement is divided into sections, one part for the winding system and gear train and the other for the chrnograph. The entire movement was designed with input from the service department so it is very easy to maintain.


Below are a series of quick pictures I took around my house using either sunlight or halogens. I myself have rarely even seen photos of this watch and prior to owning it, I had never even seen the black dialed version in person. I hope you enjoy the following pictures.


The detail on the dial is impeccable and it adheres to the traditional Daytona's two-tone sub-dials. The layout with the sub-seconds at 6 and the minute and hour totalizers on the left and righ hemisphere is optimal for a tri-compax design.


This watch has an extremely thick sapphire crystal. The profile of this watch is actually quite thin for a sports chronograph.


Here you can see that Rolex saves its best clasp for the Daytona. This is one solid bracelet and although the clasp is still of the fliplock style, it is of a much higher quality than the regular Oyster bracelets and I suspect more durable than the push button bracelets of other watches.


If you look closely at the sub-dials, you can see that their borders have a texture made of thin concentric rings, the use of white gold on the dial softens the reflection, giving the face a very elegant appearance.



The clasp utilizes an ingenious design that allows for quick adjustment without the use of tools. The extension functions somewhat like a diver's extension, a tug on the bracelet with the clasp open will extend the length a slight bit, allowing for quick and convenient micro-adjustment that really comes in handy during temperature changes.



Here is the extension in its closed position.


I have to thank my loving father for such a wonderful gift. This is a watch that I will cherish.