LIMITED EDITION OF 30 PIECES
The 2019 Singapore Formula 1 Grand Prix was the perfect occasion for the brand to present the RM 50-04 Tourbillon Split-Seconds Chronograph Kimi Räikkönen alongside our partner. The piece pays homage to both this great driver and his team: Alfa Romeo Racing Team, the legendary manufacturer inseparable from car racing.
The combination of the tourbillon escapement and the chronograph paired with the unprecedented fine skeletonisation make this particularly innovative watch the absolute chronograph perfection.
POWER RESERVE
Circa 70 hours (± 10%), without the chronograph running.
Actual power reserve results will depend on the period of time the chronograph is utilised.
ULTRALIGHT TOURBILLON CALIBRE IN TITANIUM AND CARBON TPT®
The calibre RM50-03 weighs just 7 grams and fully deserves its qualifier ‘ultralight’. The secret to its feather weight lies in the use of grade 5 Titanium and Carbon TPT®, and in the extreme skeletonisation of components. Likewise, the density, stiffness and low thermal conductivity of titanium make it a material of choice in Formula 1 engineering build programme.
BASEPLATE AND BRIDGES IN GRADE 5 TITANIUM
The baseplate and a portion of the bridges are crafted in grade 5 titanium, a biocompatible, highly corrosion-resistant and remarkably rigid alloy, which enables the gear train to function effortlessly. The alloy is 90% grade 5 titanium, 6% aluminium and 4% vanadium. This combination further increases the material’s mechanical properties, which explains its frequent use in the aerospace, aeronautics and automobile industries.
Some of the bridges belonging to the split-seconds chronograph are made from Carbon TPT®, as is the transverse carriage supporting the entire calibre, together with the barrel and tourbillon bridges. Attached to the caseband, this carriage circumvents the need for a casing ring, allowing the movement to be perfectly integrated into the case. All of these technical solutions give this complex calibre–with its extreme weight to resistance ratio–an impressive resistance capacity, tested in our workshops to shocks of 5,000 g’s.
NEW SPLIT-SECONDS SYSTEM
The Calibre RM50-03 introduces a latest-generation split-seconds mechanism developed by the Richard Mille engineers. Design of a new split-seconds mechanism and extensive research on the work of the split-seconds clamps have permitted a 50% reduction in the chronograph’s energy consumption, while at the same time reducing arbour friction. The 6-column wheel that controls the various rockers for the split-seconds function was designed to guarantee flawlessly simultaneous movement, clean function lock, and highly stable settings.
FUNCTION INDICATOR
In a manner similar to a car’s gearbox, the function indicator makes it possible to see the winding, neutral and hand-setting positions as the crown is pulled out. The active position is indicated via a hand at 4 o’clock pointing to the following functions: W (Winding) N (Neutral) H (Hands).
POWER-RESERVE INDICATOR
The power-reserve indicator shows the number of hours of energy left in the mainspring before the watch must be wound again.
TORQUE INDICATOR
This indicator supplies information about the mainspring’s tension, permitting an optimisation of the movement’s chronometric functioning. Below 53 Nmm, the spring is considered too slack, while above 65 Nmm, excess tension in the spring can adversely affect the mechanism’s operation, or actually endanger it.
FREE-SPRUNG BALANCE WITH VARIABLE INERTIA
This type of balance wheel guarantees greater reliability when subjected to shocks and during assembly or dismantling of the movement, thus providing better chronometric results over time.
The index is eliminated, thereby allowing a more precise and repeatable calibration using 4 setting screws.
WINDING-BARREL TEETH AND THIRD-WHEEL PINION WITH CENTRAL INVOLUTE PROFILE
The central involute profile of the winding-barrel teeth provides an optimal pressure angle of 20°, which promotes effective rotary motion and compensates for possible variations in the operation of the going train. This, in turn, ensures excellent torque transmission and a distinct improvement in performance.
FAST-ROTATING BARREL (6 hours per revolution instead of 7.5 hours)
This type of barrel provides the following advantages:
• The phenomenon of periodic internal mainspring adhesion is significantly diminished, thereby increasing performance.
• Provision of an excellent mainspring delta curve with an ideal power reserve/performance and regularity ratio.
MOVEMENT CHARACTERISTICS:
Movement dimensions: 31.10 x 32.15 mm
Thickness: 10.02 mm
Tourbillon diameter: 12.40 mm
Balance wheel diameter: 10.00 mm
Number of jewels: 43
Balance wheel: Glucydur®, 2 arms, 4 setting screws, moment of inertia 10 mg•cm2, angle of lift 53°
Frequency: 21,600 vph (3 Hz)
Balance spring: elinvar by Nivarox®
Shock protection: KIF Elastor KE 160 B28
Barrel shaft: nickel-free Chronifer® (DIN x 46 Cr 13 + S) with the following characteristics: stainless antimagnetic – suitable for tempering
CASE
The design and execution of the watch demonstrate a highly conceptual holistic approach to the movement, case and dial. As a result, everything has been constructed according to extremely rigorous specifications, in the manner of analytical engineering methods used in the design of Formula 1 racing cars, where the chassis and the engine are developed in complete harmony. For example, a casing ring is no longer used, and the movement is mounted on chassis mounting rubbers (ISO SW) fixed by grade 5 titanium screws. Features such as these are evidence of uncompromising workmanship.
The colors used on the C38 single-seater are showcased on the bezel and case back in white Quartz TPT. This is achieved by interlaying 600 layers of silicon each 45 microns thick and impregnating them with a white matrix before heating them to 120 °C in an autoclave. This process gives the material a very high resistance/weight ratio, non-allergenic properties, and excellent resistance to UV rays. Developed by North Thin Ply Technology, the technique is also used on the Carbon TPT caseband, but this time using carbon fibres.
The case of the RM 50-04 is water-resistant to 50 metres thanks to two Nitril O-ring seals. The case is assembled with 20 spline screws in grade 5 titanium and abrasion-resistant washers in 316L stainless steel.
TORQUE-LIMITING CROWN
This additional security system prevents accidental overwinding, which could cause damage to the winding stem or put extreme pressure on the barrel spring.
FINISHING
Movement:
• Hand-polished bevelling
• Hand-polished locking sections
• Sapphire-microblasted milled sections
• Lapped and polished contact points
• Burnished pivots
Steel parts:
• Wire-drawn and microblasted surfaces
• Hand-polished bevelling
Wheels:
• Concave chamfering with a diamond tool
• Circular-decorated front faces
• Rhodium plating (before cutting the teeth)
• Minimal corrections applied to the wheels in order to preserve geometry and performance.
MODULAR TIME-SETTING MECHANISM ON THE CASEBACK
This mechanism provides the following advantages for longevity and maintenance: Since the component is mounted outside of the movement, the time-setting assembly can be changed without affecting the integrity of the baseplate in the event of a possible defect or during maintenance. The mounting and dismantling of this module from the back does not require the removal of the hands or dial.
BARREL PAWL WITH PROGRESSIVE RECOIL
This device permits an appreciable winding gain (circa 20%), especially during the start of winding. It is also helpful in ensuring an even distribution of the mainspring’s internal tension.
SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE BRIDGES AND CASE
The design of these screws permits better control of the torque applied during assembly. These screws are therefore unaffected by physical manipulation during assembly or disassembly and age well.
