Rolex introduces the new Calibre 3255, a new-generation mechanical movement with 14 patents. Among many noteworthy items, Rolex is quick to point out that the Calibre 3255 sets a new level of chronometric precision with criteria surpassing those of COSC (the Swiss Official Chronometer Testing Institute). Rolex has developed a new methodology and high-technology equipment to test the precision of its Superlative Chronometers with tolerances that are twice as exacting as those for official certification, and under conditions that simulate the wearer’s real-life experience. Somewhat analogous to the “Patek Philippe developing its own in-house “Seal”, these exclusive Rolex chronometer tests complement the official COSC certification, to which all Rolex movements continue to be submitted systematically, and are carried out not on the movements alone, but on the assembled watches after the movements have been cased.
The 3255 incorporates the new Chronergy escapement patented by Rolex, which combines high energy efficiency with great dependability. The oscillator has an optimized blue Parachrom hairspring, which is also up to 10 times more precise than a traditional hairspring in case of shocks. Thanks to a new barrel architecture and the escapement’s superior efficiency, the power reserve of calibre 3255 extends to three days, which means a Rolex watch with the Cal 3255 can easily handle some weekend off-wrist time. The first watch to receive the new Calibre 3255 is the Oyster Perpetual Day-Date 40, featuring a modernized design with a 40mm case, available in a range of emblematic new dials. Here is the Day-Date 40 in platinum case, with very attractive, laser-etched blue dial:
CHRONERGY ESCAPEMENT AND PARACHROM HAIRSPRING
The Chronergy escapement of calibre 3255, developed and patented by Rolex, is an optimized version of the Swiss lever escapement. Its energy efficiency has been enhanced while preserving its reliability. To make it more efficient, Rolex engineers analysed the Swiss lever escapement and isolated the key parameters to be modified. The solution arrived at involved reversing the length ratios between the escape wheel teeth and the pallet stones. While the pallet stones are now only half as thick as before, the contact surfaces of the escape wheel teeth have been doubled. Moreover, the escapement elements are no longer in alignment but are slightly off-set in order to increase the lever effect. The pallet fork and escape wheel are made in nickel-phosphorus to be insensitive to magnetic interferences. 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 calibre 3255’s enhanced power reserve.
The oscillator of calibre 3255 is fitted with a blue Parachrom hairspring, patented and manufactured by Rolex in an exclusive alloy of niobium and zirconium. It is insensitive to magnetic fields and temperature variations, and up to 10 times more resilient to shocks than traditional hairsprings. You can also see its optimized Breguet overcoil, which enhances the 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 the high-precision machining have enhanced the poise three-fold.
The oscillator is attached to a new balance staff with exclusive geometry offering added resistance to magnetic interferences. It is fitted on high-performance Paraflex shock absorbers and 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.
The space inside the barrel was optimized by halving the thickness of its walls. Thereby increasing the movement’s autonomy by more than 10 hours.
SIMPLIFIED SETTING MECHANISM
The setting interface of calibre 3255 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 with no restrictions, thanks to retractable fingers inside the mechanism.
The caliber also uses new reversing wheels in the rotor architecture which provide faster, more efficient bidirectional winding, whatever the wearer’s activity. A new, monobloc, cut-out oscillating weight on a ball bearing improves shock resistance and efficiency.
The Calibre 3255 is equipped with a self-winding module via a new-generation perpetual rotor, for more rapid winding of the new high-capacity mainspring. The reversing wheel system enables winding in either direction of the weight rotation. This system, with its characteristic red wheels, 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.
The stringent test protocol mentioned in my opening paragraph was designed by Rolex following large-scale statistical studies to determine the actual conditions of daily wear. As a result, the Rolex chronometers equipped with movements tested according to this new methodology demonstrate superlative precision on the wrist.
Rolex Day-Date 40 Models – new for 2015
I’ll close with a personal thought: I don’t consider myself a Rolex Addict (though I deeply respect and admire the brand), but I am truly excited about this new caliber.