Above and beyond the first impression of technical beauty and sophistication, this watch sparks natural curiosity. Is it a skeletonised watch? No, it did not involve openworking the movement parts to let the light through. So has the dial simply been pierced in order to reveal part of the mechanism? Not exactly, and nor was it just a matter of making openings in the mainplate so as to see through it. In any case, one thing is for sure: the watchmakers from Le Brassus have accomplished the feat of putting an object on your wrist that is more movement than watch.
They are thereby fulfilling the dream of all watchmaking devotees: extracting the fine mechanism from the cavity of its case to reveal it in all its splendour. This means there is no longer any need to turn the watch over to admire the movement through a sapphire crystal caseback, because the movement of the Millenary 4101 has actually been built to show itself face upwards. An intriguing notion that is sure to satisfy the curiosity of the most discerning aesthetes and connoisseurs! This fascinating spectacle is staged within the perimeter of a shaped case – and not just any case, but the voluptuous and sophisticated oval that makes the Millenary collection so truly unique.
Revealing the beating heart of the watch – Have you ever savoured the magic of certain homes in which the surrounding garden seems to be an integral part of the living areas, as if the foliage of the trees extended into the lounge, and the settee and coffee table appear to be set amongst the greenery? The Millenary 4101 exercises the same fascination as this holistic architecture. It blurs the borders between inside and outside. It overturns existing ideas, and in particular that which holds that the design involves the exterior of the watch – dial, case and wristband – and thus its outer garment, while the inside is essentially functional. Things are very different on this model, in which the inside and outside form a seamless whole merging functionality and design. In terms of development and production, this naturally implies intense cooperation between the teams at work, resulting in two highly original models, one in stainless steel with a black crocodile leather strap, and the other in pink gold with a brown crocodile leather strap, and both masterfully combining form and content.
Calibre 4101, entirely designed, developed and produced in-house, was built in such a way that the elements normally concealed on the back are now visible from the front. The regulating organ – composed of the balance, lever and escapement – has been reworked in order to meet this goal. It is located at 9 o’clock and offers a truly eye-catching sight. Its variable-inertia balance asserts a powerful presence with its eight inertia-blocks, its golden colour and the distinctive aesthetic of its cross-through bridge. The discerning eye will even detect the lever and the escape-wheel.
Moreover, no less than 12 bridges have been cleverly arranged on the surface of the movement. In addition to their functional role, which consists in holding the various parts in place, they also serve as attractive design elements, including by tracing three beautiful parallel curves on the dial side. Their decorative motifs – horizontal Côtes de Genève, circular graining; and snailing on the “trottoirs” – play with the different movement levels to accentuate the contrasts and depth effects. The screws on the left-hand side of the dial underscore the oval shape of the case and create a more technical and richer overall impression. The same goes for the hemispherical convex and particularly sparkling jewels punctuating the 10, 11 and 12 o’clock numerals on the dial.
In this manner, various elements relating to the movement structure and its functional role in fact play a premier role in the overall aesthetic appeal of the watch. They merge as one with the signature characteristics of the Millenary collection represented by the oval case subtly accentuated by the contrast between the brushed case middle and the polished bezel, as well as the offset subdial with Roman numerals. The watch is thus viewed as a sophisticated whole distinguished by its three-dimensional, high-tech design. The Millenary 4101 thereby pursues an exploratory process that began several years ago and has been exemplified through models such as the Tradition d’Excellence N°5, the Millenary with deadbeat seconds and the Millenary MC 12.
Reliability, timing precision and finishing quality – The oval Calibre 4101, as we have seen, is distinguished by an ingenious structural approach that turns the parts upside down and plays a key role in the overall design of the watch. Nonetheless, these visual qualities must not eclipse its excellent reliability. The heart of the movement is a variable-inertia balance with eight white gold inertia-weights that ensures improved long-term rating stability. Equipped with a Breguet balance-spring, it beats at an oscillation frequency of 4 Hz, meaning 28,800 vibrations per hour. This oscillation frequency, along with the higher inertia of the balance, improves the timing precision and also makes the regulating organ less sensitive to external disturbing factors. The cross-through balance-bridge ensures improved shock resistance due to the fact that it is secured not just on one side, but on either side of the mainplate.
Winding is ensured by a 22-carat gold oscillating weight mounted on ceramic ball bearings. The reverser mechanism ensuring bidirectional winding is also composed of a ceramic ball-bearing system. An effective antidote to wear and also useful in avoiding any locking, the system is conducive to optimal winding speed. The mainspring thus wound is able to release its energy in a more regular manner and to positively influence rating precision.
Hand-decorated and assembled in the Le Brassus workshops, Calibre 4101 boasts exceptionally high-quality execution and finishing. The movement of the steel version has an elegantly understated colour achieved by an anthracite galvanic treatment, while that of the pink gold version is rhodiumed and gilded. The bridges are meticulously bevelled and polished so as to display only clean-cut, gleaming edges. The jewel sinks are diamond-polished. The wheels have bevelled spokes and diamond-polished sinks. Even the screw rim and slots are bevelled. The mainplate is decorated on both sides: Côtes de Genève on the front and circular-graining in two different sizes on the back in order to create greater contrast and depth effects. The bridges on the dial side feature horizontal Côtes de Genève, snailing and circular graining, while the bridges on the back are distinguished by circular Côtes de Genève, snailing and circular graining. Finally, the 22-carat gold oscillating weight is adorned with the Audemars and Piguet family crests and the AP monogram.
Movement – Proprietary selfwinding Calibre 4101. Overall dimensions – (width/length: 37.25 x 32.90 mm). Casing diameter – (width/length: 36.75 x 32 mm). Thickness: 7.46 mm. 34 jewels. 253 parts. Bidirectional winding 22-carat gold oscillating weight mounted on ceramic ball bearings. 60-hour power reserve. Cadence of the balance: 28,800 vibrations per hour (4 Hz). Variable-inertia balance with eight inertia-blocks and Breguet overcoil balance-spring. Screw-down mobile balance-spring stud-holder.
Finishing – All parts decorated by hand; mainplate adorned with horizontal Côtes de Genève on the front and circular-grained on the back; bridges rhodiumed, bevelled, snailed and adorned with horizontal and circular Côtes de Genève and with circular graining: Diamond-polished jewel sinks; diamond-polished countersinks and bevelled wheel spokes; bevelled screw rims and slots. AP monogram as well as Audemars and Piguet family crests engraved on the oscillating weight.
Functions – Hours and minutes. Small seconds.
Cases – Stainless steel or 18-carat pink gold. Dimensions – (width/length: 47 x 42 mm). Thickness 13 mm. Sapphire crystal caseback.
Dials – Directly fixed to the bridges. Black and anthracite with applied pink gold Roman numerals. Pink gold hands.
Water resistance – 20 m.
Straps – Hand-sewn black or brown crocodile leather with large square scales, secured by an AP folding clasp in stainless steel or 18-carat pink gold.
Source: Audemars Piguet