The Rolex Caliber 3135

The Rolex Caliber 3135

Nov 09

The Rolex Caliber 3135
By: John B. Holbrook, II
November 9th, 2010

Rolex is a name which needs no introduction in or outside the world of horology.  Rolex is also renowned for historical innovations in horology, such as the water-resistant Oyster case (1926), and the Perpetual auto­matic winding system (1931). Rolex has continued to develop significant innovations, as evidenced in what is per­haps one of the maker’s most significant horological contri­butions in the modern era, the Rolex Caliber 3135.

First introduced in 1988, the Caliber 3135 has quickly become Rolex’s workhorse movement. From the classically styled Datejust models to the functionally demanding Professional series watches such as the Submariner (date models), Sea-Dweller and Yacht-Master, the Rolex 3135 has found its way into more Rolex watches than any other movement and is arguably the most successful caliber Rolex has ever produced. Why has the Rolex caliber 3135 been such a success for nearly 20 years?

The first factor—and perhaps the most significant fac­tor—in understanding the superior design of the Rolex 3135 is the size of the caliber itself. At 26.5mm in diameter and 6mm high, the 31-jewel Rolex 3135 is quite large for a modern movement. From an engineering standpoint, the larger size means the movement is inherently more robust and can incorporate parts and components with higher tolerances, which translates to performance that is highly durable, reliable and stable. The caliber 3135 also incorporates several components that contribute greatly to the movement’s performance.

The Glucydur balance wheel of the 3135 uses the Microstella system for making minor adjust­ments in timing. The system is comprised of four screws at equidistant points along the balance wheel. If they are moved toward the center of the balance wheel, the rate will speed up. Moving them away from the center slows the rate. Rolex has smartly designed the caliber 3135 with a free-sprung balance as well as a Breguet overcoil. While Rolex manufactures nearly every part inside the Caliber 3135, the hairspring is made by Nivarox (though recent examples of the 3135 use the Rolex manufactured “Parachrom Bleu” hairspring) . Rolex also incorporates KIF shock protection to further guard against timing errors due to sudden movement—this is particularly necessary because the Rolex 3135 is often used in the Professional and Sport models exposed to harsh and rigorous conditions. Rolex has engineered the Caliber 3135 balance to maintain frequency of 28,800 bph.

The caliber 3135 incorporates a Perpetual wind­ing system reminiscent of the Perpetual automatic winding system Rolex invented back in 1931. The winding rotor of the 3135 is extremely efficient due to bidirectional functionality—the rotor winds the mainspring in either direction of rota­tion. It’s also silent when in operation—virtually no noise is perceptible when the rotor is spinning. Two winding gears in the system provide the bidi­rectional winding functionality, and the light alloy gears are coated with PTFE (commonly known by the brand name Teflon). The coating enhances winding efficiency and gives the gears a deep red color. I know of no other movement manufacturer who uses such a coating. In fact, the red gears have become a Rolex calling card that can distin­guish the genuine article from a counterfeit move­ment. The Rolex 3135 has approximately 50 hours of power reserve when fully wound. If the winding system has any sort of an Achilles heel, it would be that Rolex, unlike most manufacturers, does not use ball bearings in the axle of the oscil­lating rotor. Instead, Rolex uses a plain sleeve bearing, which makes the winding system particularly vulnerable to failure if not regularly serviced.   Fresh, clean lubricant is key to maintaining functionality. However, if properly lubricated and serviced, the Rolex 3135 has the potential to last for decades, if not lifetimes.

From an accuracy standpoint, the Rolex 3135 is a champion. Before it leaves the factory, the Caliber 3135 is adjusted in five different positions and for various changes in temperature, and it is rigorously tested by Rolex for accuracy. Only then does Rolex submit the Caliber 3135 to the prestigious Contrôle Officiel Suisse des Chronomètres (COSC) for chronometer certification. According to COSC certification statistics, year after year, Rolex produces the highest number of chronometers of any mechanical movement manufacturer. No doubt this is due in part to the success of Caliber 3135.

As marvelously engineered and functional as the 3135 is, it certainly won’t win any beauty contests. There is not the same attention paid to meticulous finishing and fine decoration as one will find in, say, a Jaeger-LeCoultre or Blancpain movement. Even the winding rotor of the 3135 is absent of the usual ornate logos and decorations, but it does feature the traditional slots found on most Rolex rotors. Absent too are such elegant features as swan’s neck regulators or micro winding rotors—such features and ornate decorations are quite contrary to the purpose for which the Rolex 3135 was designed—to be a robust, durable and highly accurate movement. It was never intended to look “pretty” which is why most Rolex watches (excluding the newly introduced Prince models) do not have display case backs. If one were to conclude, however, that Rolex puts no effort or craft into the manufacture and finishing of its movements, one would be quite mistaken. Take for example the decoration present on the bridges and plates in the 3135. They are finished with circular graining. This has more than just a decorative purpose—it also provides for better dust protection. Rare is the Rolex design feature that does not have a practical, functional purpose. The surfaces of the bridges are also rhodium plat­ed, and the edges are beveled. Certainly there is no fault­ing the craftsmanship of the Rolex 3135.

While the Rolex 3135 is humble in appearance, and boasts no exotic complications, it is without a doubt one of the best movements ever created by Rolex, and quite arguably one of the top calibers of the twentieth century.

You can discuss this article in the Rolex Forum of my online luxury watch discussion forum community WATCH TALK FORUMS.