Built to Last

The next generation of in-house Rolex movements represents a new era of performance.


By: Jon Bues

Rolex’s global reputation for a steady hand and a risk-averse approach to watchmaking is likely matched only by Patek Philippe’s. And yet, those two firms are famously responsible for many of the most important innovations that define the modern wristwatch. When Rolex judges that an innovation will have staying power and promises improved performance, it draws on its vast R&D department, which is constantly generating ideas. After all, Rolex gave us the first waterproof wristwatch in 1926, received the first chronometer certification for a watch in 1910, and was the first watchmaker to simultaneously display dual time zones with the GMT.

Rolex typically doesn’t go for a wow factor when it updates its products’ technical specifications. Instead, their focus is on improving performance in subtle ways that all add up to practical quality and reliability for watch owners. Though this publication would never advise that watch owners let regular service intervals fall to the wayside, I have seen many Rolex owners go beyond suggested service times while their watches continue to run with chronometric precision. This I can only attribute to a manufacturing process that has been refined to account for hard wear in the real world.

The front facing side of Calibre 3235. Thanks to some clever engineering, the date can be changed at any time.
The front facing side of Calibre 3235. Thanks to some clever engineering, the date can be changed at any time.

Last year, Rolex released the Caliber 3235, which debuted inside the Datejust 41 and appears likely to become the flagship automatic movement with date in future releases. The improvements of Caliber 3235, which together account for some 14 patents, are manifestly aimed at improving precision and efficiency. Ninety percent of the components have never been used before, making it a truly original and state-of-the-art movement.

It is only the second Rolex movement to come from a new generation of in-house calibers that feature the new Chronergy escapement—first seen in the Caliber 3255 of 2015—developed in-house by, and exclusive to, Rolex.

This escapement, an evolution of the conventional Swiss Lever, was achieved through a reversal of the ratios between the escape wheel teeth and the pallet stones. The pallet stones are now half as thick as they were before, and the contact surfaces of the escape wheel teeth have been doubled. The escape wheel itself and the pallet fork are made from nickel phosphorous, a material chosen for its antimagnetic properties.

Why fiddle with what was already a very serviceable Swiss Lever escapement, one might ask? The modifications increase efficiency by approximately 15 percent, which in turn has contributed to an increase in the watch’s power reserve.

That lengthy power reserve—now 70 hours—is also boosted by a high-capacity barrel. Without increasing the size of the barrel even a micron, Rolex fitted a longer, high-capacity mainspring that accounts for an additional 10 hours of autonomy. The new barrel has particularly thin walls, allowing more spring to be wound inside without taking up any additional space.

A rear view of the 3235, whose highly efficient winding comes courtesy of a rotor turning on ball bearings.
A rear view of the 3235, whose highly efficient winding comes courtesy of a rotor turning on ball bearings.

Other highlights include the use of a proprietary Parachrom hairspring. Made from an exclusive alloy of niobium and zirconium, the blue-colored hairspring is immune to the deleterious effects of magnetic fields. This spring is paired with an oversized balance wheel that enables easy adjustments and precision regulation by the watchmaker.

High-efficiency winding comes via a new system that has the rotor turning on ball bearings. New reversing wheels in the system provide efficient bidirectional winding, and a new rotor shape increases the speed of the oscillating mass, which in turn feeds more energy to the barrel.

This high-efficiency winding is complemented by a reengineered gear train, which is further enhanced by exclusive new lubricants that Rolex synthesizes in-house. Every watchmaker needs to oil movements to make them run smoothly, but Rolex is the only watchmaker that actually makes its own oils.

The new movement also comes with a gear train that has been engineered for better efficiency.
The new movement also comes with a gear train that has been engineered for better efficiency.

Improvements to the time-setting system are displayed in better ergonomics, faster adjustment of the time, the ability to correct the date any time the wearer wants to (the dreaded “not between 10 and two rule” doesn’t apply to this caliber), and very precise time setting. Upon extending the crown of watches equipped with Caliber 3235, one senses distinctive clicks.

So you can see, Rolex’s latest generation of in-house automatic movements offers the kind of improvements that collectors expect from the brand—precision, durability, and quality of construction.