Sea‑Dweller 126662 replica

This year marks the 50th anniversary of the Rolex Explorer II, and the 3285 calibre has become the heart of the Rolex Explorer II. It is estimated that many friends have not noticed that compared with the time when it was first launched 3 years ago, this year’s 3285 calibre has a small change: the number of balls in the automatic gyroscopical ball bearing is close to 30, while the previous number of balls was generally 7, nearly 4 times more.

A closer look at the central part of the diagram above shows that although it is the same calibre 3285, the number of balls inside the bearing structure is different. So I looked at the other movements that Rolex is currently producing, and the 3230, 3235, 4130, 9001, etc., all have seven-ball bearings. In this way, this year’s Calibre 3285 is Rolex‘s forerunner in the field of multi-ball bearings. Will other movements follow suit in the future? I’m sure they will. In 1948, the watchmaker Heinrich Stamm invented the five-ball bearing structure and applied it to the Eterna Matic automatic movement.

The advantage of this design is that it can greatly reduce the bearing pressure, allowing the rotor to rotate more smoothly, which in turn improves the efficiency and precision of winding, which is very beneficial for the low-load mechanical transmission structure of a watch.

As a result, after the patent period, the manufacturers began to use this design, and even Rolex introduced the first Calibre 4130 to use ball bearings in 2000, which it has been using ever since. In addition to Rolex, Patek Philippe, Audemars Piguet, and other major manufacturers are also using ball bearings, and the increasing number of balls has become a trend, which is why I think that in the future, the entire line of Rolex movements will cover multi-ball bearings.

Similarly, Audemars Piguet‘s 4308 automatic calibre, which was launched this year, is based on the 4302 adaptation and upgrade, and the architecture of the two is almost the same, but the number of automatic gyroscopic bearings has skyrocketed from the original 7 to nearly 50 today.