Datejust 41

OYSTER PERPETUAL 

DATEJUST 41

Rolex is introducing the new generation of its classic Oyster Perpetual Datejust, featuring an updated design in a 41 mm case and the new Rolex calibre 3235, a movement at the forefront of watchmaking technology. The new Datejust 41 is offered in yellow or Everose Rolesor versions – a combination of 904L steel and either 18 ct yellow or Everose gold – with a wide selection of dials. 
 
The new Datejust 41 carries the Superlative Chronometer certification redefined by Rolex in 2015, which ensures singular performance on the wrist.

ARCHETYPE OF THE CLASSIC WATCH

Rolex’s Datejust is the archetype of the classic watch thanks to functions and aesthetics that never go out of fashion. Launched in 1945, it was the first self-winding waterproof chronometer wristwatch to display the date in a window at 3 o’clock on the dial, and consolidated all the major innovations that Rolex had contributed to the modern wristwatch until then. Aesthetically, the Datejust has spanned eras while retaining the enduring codes that today still make it one of the most recognized and recognizable of watches.

ROLESOR, A MARRIAGE OF GOLD AND STEEL

Rolesor, the combination of gold and steel on a Rolex watch, has been a signature feature of the brand since 1933, when the name was registered. It is an auspicious meeting of two metals: one, noble and precious, attractive for its lustre and stability; the other, highly resistant, known for its strength and reliability. All of these qualities perfectly mirror the elegance and performance that come together in a Rolex watch. The Rolesor concept is simple: the bezel, the winding crown, as well as the centre bracelet links are made of 18 ct yellow or Everose (Rolex’s exclusive patented pink gold alloy) gold; the middle case and the outer links of the bracelet are made of 904L steel. Introduced on the Datejust in 1948, Rolesor contributed largely to the legendary status of this wristwatch.

THE OYSTER CASE, SYMBOL OF WATERPROOFNESS

The Oyster case of the Datejust 41, guaranteed waterproof to a depth of 100 metres (330 feet), is a paragon of robustness, proportion and elegance. The characteristically shaped middle case is crafted from a solid block of 904L steel. The fluted case back is hermetically screwed down with a special tool that allows only Rolex watchmakers to access the movement. Fitted with the Twinlock double waterproofness system, the winding crown screws down securely against the case. The crystal, with a Cyclops lens at 3 o’clock for easy reading of the date, is made of virtually scratchproof sapphire. The waterproof case provides optimum protection for the Datejust 41’s high-precision movement.

PERPETUAL CALIBRE 3235

The Datejust 41 is equipped with calibre 3235, a new-generation movement entirely developed and manufactured by Rolex. This self-winding mechanical movement is at the forefront of watchmaking. A consummate demonstration of Rolex technology, with 14 patents, it offers fundamental gains in terms of precision, power reserve, resistance to shocks and magnetism, convenience and reliability. It incorporates the new Chronergy escapement patented by Rolex, which combines high energy efficiency with great dependability. Made of nickel-phosphorus, it is also insensitive to magnetic interference.

An optimized blue Parachrom hairspring is fitted to the oscillator, thetrue heart of the watch. Patented and manufactured by Rolex in an exclusive paramagnetic alloy, it is also up to 10 times more precise than a traditional hairspring in case of shocks. A Rolex overcoil ensures its regularity in any position. Calibre 3235 is equipped with a self-winding module via a Perpetual rotor. Thanks to a new barrel architecture and the escapement’s superior efficiency, the power reserve of calibre 3235 extends to approximately 70 hours.

OYSTER AND JUBILEE BRACELETS

The new Rolesor Datejust 41 is available on an Oyster or Jubilee bracelet. Both bracelets, combining 904L steel and 18 ct gold, benefit from the new concealed attachment beneath the bezel, which ensures seamless visual continuity between the bracelet and case. They are equipped with a folding Oysterclasp and also feature the ingenious Rolex-patented Easylink rapid extension system that allows the wearer to easily increase the bracelet length by approximately 5 mm, for additional comfort in any circumstance.

SUPERLATIVE CHRONOMETER CERTIFICATION

The Datejust 41 is covered by the Superlative Chronometer certification redefined by Rolex in 2015. This exclusive designation testifies that the watch has successfully undergone a series of tests conducted by Rolex in its own laboratories according to its own criteria, which exceed watchmaking norms and standards. The certification applies to the fully assembled watch, after casing the movement, guaranteeing superlative performance on the wrist in terms of precision, power reserve, waterproofness and self-winding. The precision of a Rolex Superlative Chronometer after casing is of the order of −2/+2 seconds per day, or more than twice that required of an official chronometer. The Superlative Chronometer status is symbolized by the green seal that comes with every Rolex watch and is coupled with an international five-year guarantee. Superlative Chronometer

CALIBRE 3235 IN DETAILS

NEW-GENERATION ROLEX MOVEMENTS 

A new-generation mechanical movement with 14 patents that embodies the brand's new standards of performance with its precision, power reserve, reliability, resistance to shocks and magnetism, as well as the ease and convenience of its adjustment.

FOURTEEN PATENTS

A compelling example of avant-garde watchmaking technology, this self-winding mechanical movement is entirely developed and manufactured by Rolex. It is backed by 14 patents and a number of innovative technological solutions relating not only to component design but also to processes involving new technologies that push back the limits of existing production methods. More than 90 per cent of the movement parts have been redesigned and optimized, from those that produce and store energy (self-winding module and mainspring) to the regulating organ responsible for precision (oscillator), the gear train and the escapement. The escapement, which transmits the impulses required to maintain the oscillator’s steady beat, is enhanced by a major innovation patented by Rolex under the name Chronergy.

NEW CHRONERGY ESCAPEMENT 

Rolex engineers devised and patented a new escapement that optimizes the efficiency of the Swiss lever escapement, the standard technical solution in Swiss watchmaking, but which has seen only limited evolution over the last 50 years. While favoured by watchmakers for its great reliability, the Swiss lever escapement has always suffered from low efficiency, relaying to the oscillator barely more than a third of the energy it receives from the mainspring via the gear train.

The result of extensive research, the geometry of the new Rolex Chronergy escapement improves the efficiency of this key component by 15 per cent. Almost half of calibre 3235's increased power reserve can be ascribed to the escapement itself. Made of nickel-phosphorus, the Chronergy escapement is, furthermore, insensitive to magnetic interference.

SUPERLATIVE CHRONOMETER CERTIFICATION

Like all Rolex watches, the models equipped with calibre 3235 benefit from the Superlative Chronometer certification redefined by Rolex in 2015. This exclusive designation testifies that they have successfully undergone a series of tests conducted in the brand's own laboratories according to its own criteria, which are more stringent than watch-making norms and standards. These tests are carried out on each fully assembled watch, after casing the movement, in order to guarantee superlative performance on the wrist.

The precision of every movement – officially certified as a chronometer by COSC (Swiss Official Chronometer Testing Institute) – is tested a second time by Rolex after being cased, to ensure that it meets criteria for precision that are far more exacting than those for an official chronometer. The tolerance for the average rate of a Rolex Superlative Chronometer after casing is of the order of −2/+2 seconds per day. Its precision is tested by Rolex using an exclusive methodology that simulates the conditions in which a watch is actually worn and is much more representative of real-life experience. The certification testing is carried out using state-of-the-art equipment specially developed by Rolex. The entirely automated series of tests also checks the waterproofness, the self-winding capacity and the power reserve of every Rolex watch. These tests systematically complement the qualification testing upstream during development and production that ensures the watches’ reliability, robustness, and resistance to magnetism and shocks.

The unique way in which Rolex watches are designed, manufactured and tested, together with the exclusive innovations from which they benefit, push back the limits of performance for mechanical watches and make Rolex the benchmark for watchmaking excellence. The Superlative Chronometer status is symbolized by the green seal that comes with every Rolex watch and is coupled with an international five-year guarantee.

AESTHETIC HERITAGE

Calibre 3235 benefits from new, updated aesthetics, both in the shape and arrangement of the bridges as well as in their meticulous, trad - itional decoration. The aesthetics have evolved while preserving the characteristic features of Rolex Perpetual movements, such as the red reversing wheels of the self-winding module, the golden yellow sinks, and the traversing balance bridge. Calibre 3235 consequently remains firmly in the aesthetic lineage of Oyster watch movements.

AN INDUSTRIAL CHALLENGE

The exceptional performance of calibre 3235 is the result of years of research and development on horological components by Rolex engineers. It is also made possible by the Manufacture's in-house expertise, covering all the processes involved in movement production. This know-how has pushed back the boundaries of production methods in terms of precision and tolerances, leading to enhanced component quality and performance. For example, through high-precision machining, the thickness of the walls of the barrel has been reduced by 50 per cent, resulting in a more than 10-hour gain in autonomy.

The synthetic ruby pallet stones on the new Chronergy escapement’s pallet fork measure a mere 125 microns, half the size of the previous generation’s. Precision manufacturing ensures a threefold enhancement in the poise of the oscillator balance wheel. High-technology manufacturing processes are also used, such as LiGA (micro-manufacturing by electroforming) to produce the paramagnetic pallet fork and escape wheel of the new Chronergy escapement.

KEY COMPONENTS OF CALIBRE 3235

The entire mechanism of the 3235 movement has been optimized, from the oscillator - the guardian of precision - to the self-winding module that supplie its energy.

PARAMAGNETIC OSCILLATOR WITH PARACHROM HAIRSPRING

The oscillator is the heart of a mechanical movement. Comprising a hairspring and a balance wheel, this regulating organ determines the precision of the watch by the regularity of its oscillations. The oscillator in a Rolex watch beats eight times per second, or more than 250 million times per year. For an oscillator to maintain its regularity, it must be able to resist external factors that can disrupt its performance, such as temperature variations, shocks, magnetic fields and the influence of gravity in different positions.

The oscillator of calibre 3235 is fitted with a blue Parachrom hairspring, patented and manufactured by Rolex in an exclusive alloy of niobium, zirconium and oxygen. Insensitive to magnetic fields, the Parachrom hairspring offers great stability in the face of temperature variations and remains up to 10 times more precise than a traditional hairspring in case of shocks. It is equipped with an optimized Rolex overcoil ensuring excellent isochronism of the oscillations in any position.

The large balance wheel with variable inertia is fitted with four gold Microstella nuts enabling extremely precise regulating. Its redesigned geometry and high-precision machining have enhanced the poise threefold.

The oscillator is attached to a new balance staff with exclusive geometry offering increased resistance to magnetic interference. It is fitted on high-performance Paraflex shock absorbers developed and patented by Rolex for increased resistance to shocks. The oscillator is held firmly in place by a traversing bridge, further reinforcing shock resistance. The balance bridge features an optimized height-adjustment system and new integrated protection for the balance wheel.

CHRONERGY ESCAPEMENT WITH OPTIMIZED EFFICIENCY

The escapement plays a major role in how the movement functions. Its alternating beats produce the familiar “tick-tock“ of mechanical watches. Positioned between the gear train and the oscillator, it is the “key to time“.

The escape wheel receives raw energy from the mainspring through the gears and transmits it to the oscillator via impulses from the pallet fork. The oscillator's regular back-and-forth motion determines the division of time, which the escapement in turn transmits to the hands via the gear train.

This crucial system must function reliably so as not to hinder the movement rate. Its alternating movement and the friction generated between parts occasion considerable energy loss. For this reason, the escapement is one of the parts with the greatest potential for improvement in a mechanical watch.

The Chronergy escapement of calibre 3235, developed and patented by Rolex, is an optimized version of the Swiss lever escapement, the standard escapement used in mechanical watches. The Chronergy escapement enhances the Swiss lever escapement's energy efficiency while preserving the reliability for which it is renowned.

In order to develop greater efficiency, Rolex engineers analysed the functioning of the Swiss lever escapement using cutting-edge observation methods and numerical modelling. The solution they arrived at was to reverse the length ratios between the escape wheel teeth and the pallet stones (see box). Furthermore, the escapement system is no longer in alignment but slightly offset, affording greater distance between the pivots of the pallet fork and the balance wheel, thus multiplying the lever effect.

The pallet fork and escape wheel are made in nickel-phosphorus, to be insensitive to magnetic interference. The pallet stones are synthetic rubies, as in a conventional escapement. The escape wheel has a cut-out design to make it lighter and reduce its inertia.

Together, these modifications to the geometry have increased the efficiency of the escapement by 15 per cent, contributing to almost half of the gain in calibre 3235's power reserve.

EFFICIENT GEAR TRAIN

The gear train is the series of cogwheels that transmits energy from the barrel to the escapement. Through its different wheel sizes and gear ratios, it transforms the beats of the oscillator into the seconds, minutes and hours displayed by the hands. Correct lubrication of this mechanical assembly, and high-quality lubricants are essential to ensure the proper functioning of the movement and its continued reliability over many years.

The efficiency of the gear train has been optimized. Rolex has also developed, and synthesizes in-house, exclusive new high-performance lubricants with a considerably longer useful life and greater stability over time. Rolex is the only independent watch manufacturer to develop and synthesize its own lubricants.

HIGH-CAPACITY BARREL

The barrel supplies energy to the movement. It contains the mainspring, whose powerful coils store the energy produced when the movement is wound, either manually or through a self-winding system. As the mainspring uncoils, it releases a continuous flow of energy, which is controlled by the alternating beats of the escapement. Energy from the mainspring is transmitted to the escapement and the oscillator through the gear train. The movement’s autonomy or power reserve between windings depends, therefore, on how much energy the mainspring can store and on the energy efficiency of the gear train and the escapement-oscillator assembly. If the power reserve is to be increased, it means either improving the escapement's efficiency or enlarging the mainspring – or both, as Rolex has done with calibre 3235.

Space is at a premium inside a watch movement. To increase the capacity of the mainspring in calibre 3235 without increasing the size of the barrel housing it, Rolex decided to optimize the space inside the barrel by halving the thickness of its walls. This solution represented a considerable challenge both for machining and for the production process, pushing back the boundaries of current production methods. The resulting gain in space allowed for the accommodation of a mainspring with greater capacity, thereby increasing the movement's autonomy by more than 10 hours.

ACCELERATED SELF-WINDING

Energy stored by the mainspring must be regularly renewed, otherwise the movement would stop once it had used up its power reserve. Traditionally, mainsprings were hand wound, via the winding crown. In 1931, Rolex played a pioneering role in developing a self-winding system for a wristwatch, which it patented at the time and named the Perpetual rotor. This mechanism, with its half-moon-shaped oscillating weight, continually winds the mainspring using nothing more than natural wrist movements. As a result, it supplies the movement with a steady and "perpetual" source of energy for as long as the watch is being worn.

Calibre 3235 is equipped with a self-winding module with a new-generation Perpetual rotor, for more rapid winding of the new high-capacity mainspring. The reversing wheel system enables winding in both directions of the weight rotation. This system has been optimized to reinforce its efficiency whatever the activity of the wearer. The now monobloc oscillating weight has been cut out to absorb shocks. It is fitted on a ball bearing and is held at its centre by a single screw, thereby facilitating assembly.

SIMPLIFIED SETTING MECHANISM

The winding crown is the main interface between the watch movement and the wearer, who uses it to manually wind the movement or to set the time and functions. A sophisticated mechanism inside the movement activates the settings that correspond to the various positions of the winding stem.

The setting interface of calibre 3235 is more ergonomic and user-friendly. The stops marking the positions of the winding crown are distinct and easily sensed. The setting system has been optimized, making for faster day and date adjustment. Time setting is very precise with no play. The calendar can be corrected at any time, without restriction, thanks to retractable fingers inside the mechanism.