TECHNICITY AT THE SERVICE OF ADVENTURE
RM 25-01 TOURBILLON CHRONOGRAPH ADVENTURE
Manual winding tourbillon movement with 24-hour display, minutes, seconds, chronograph, 30-minute totaliser, power-reserve, torque and function indicators.
Limited edition of 20 pieces
Circa 72 hours (± 10%), 65 hours with the chronograph running.
Actual power-reserve results will depend on how extensively the chronograph is utilised.
Grade 5 titanium is a biocompatible, highly corrosion-resistant and remarkably rigid alloy, which enables the gear train to function effortlessly. The alloy is 90% 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.
The baseplate and bridges have been subjected to intensive and complete validation tests to optimise their resistance capacities.
COMPETITION CHRONOGRAPH MOVEMENT
Richard Mille engineers spent several months of work and research reducing the weight and optimising the calibre, especially the precision of time calculation over the long term.
This has given rise to many innovations, such as the design and manufacturing of several titanium parts, like the levers, which reduce inertia and thus lower energy consumption by 50%. This made it possible to significantly alleviate friction on the axis and eliminate jumps and twitches of the chronograph hand during start or stop of the timer.
The RM 25-01 development was especially slow and painstaking, and as an object it is completely in sync with the brand: extreme, designed for extreme conditions, useful, sophisticated and complex, yet unbelievably tough.
In a manner similar to a car’s gearbox, the function indicator makes it possible to identify 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 that indicates the function as follows: W (Winding) – N (Neutral) – H (Hands).
This indicator supplies information about the mainspring’s tension, thus permitting an optimisation of the movement’s chronometric functioning. Below 5.3 N.mm, the spring is considered too slack, while above 6.5 N.mm, excess tension in the spring can adversely affect the mechanism’s operation, or actually endanger it.
The power-reserve indicator shows the number of hours of energy left in the mainspring before the watch must be wound again.
The free-sprung balance offers better reliability in the event of shocks, movement assembly or disassembly, and also guarantees better chronometric results over time. The regulator index is eliminated, and a more accurate and repeatable calibration is possible thanks to 4 small adjustable weights located directly on the balance.
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 dimensions: 38.95 mm
Thickness: 8.37 mm
Tourbillon diameter: 12.30 mm
Balance wheel diameter: 10.00 mm
Number of jewels: 35
Balance wheel: Glucydur®, with 2 arms and 4 setting screws
Moment of inertia: 11.50 mg.cm2, angle of lift 53°
Frequency: 21,600 vph (3 Hz)
Balance spring: elinvar by Nivarox®
Shock protection: KIF ELASTOR KE 160 B28
Central bridge in titanium
Barrel shaft: nickel-free Chronifer® (DIN x 46 Cr 13 + S), with the following characteristics: stainless – antimagnetic – suitable for tempering
Carbon TPT® is an exclusive material with a unique damascene appearance. Its remarkable surface displays extremely regular striations, as Carbon TPT® is composed of many layers of parallel filaments obtained by dividing carbon fibres. These layers, with a maximum thickness of 30 microns, are impregnated with resin, then woven on a special machine that modifies the direction of the weft by 45° between layers. Heated to 120°C at a pressure of 6 bars, the Carbon TPT® is then ready to be processed on CNC machines at Richard Mille’s parts factory.
The case of the RM 25-01 is water resistant to 100 metres, ensured by two Nitrile O-ring seals. The case is assembled with spline screws in grade 5 titanium and abrasion-resistant washers in 316L stainless steel.
The compass consists of a fixed bezel and a rotating bezel, both crafted in DLC-treated grade 5 titanium, with sapphire glass. It attaches to the case with a bayonet mount. Its cover is made of Carbon TPT®, and includes a mirror with an opening at 12 o’clock that permits greater precision when orientating with the compass needle.
Once removed, the compass can be affixed to a Carbon TPT® baseplate. Ideal for orientation, this arrangement provides a number of indications, including engraved lines showing the direction to head in when following a course with a map.
BIDIRECTIONAL DAYTIME BEZEL
The titanium bezel can be exchanged for a ‘daytime’ bezel should the owner so desire.
This second bezel, in Carbon TPT® and grade 5 titanium, possesses marks for the four cardinal directions in addition to a 360° graduated disk and a 24-hour scale.
The spirit level contained within a titanium bubble makes it possible to hold the watch exactly horizontal to improve accuracy when sighting with the compass needle.
WATER RESISTANT COMPARTMENT
This module, in grade 5 titanium, is hermetically sealed to stash water purification tablets that can make any source of water safe to drink.
This added security system prevents accidental overwinding of the watch, which can cause damage to the winding stem or place extreme pressure on the barrel spring.
• Hand-polished bevelling
• Hand-polished locking-sections
• Sapphire-microblasted milled sections
• Bridges hand drawn following PVD treatment
• Lapped and polished contact points
• Burnished pivots
• Sapphire-blasted and hand-drawn surfaces
• Screw slot and screws bevelled and polished with rounded and polished tip
• Concave chamfering with a diamond tool
• Circular-finished faces
• Rhodium plating (before cutting the teeth)
• Minimal corrections applied to the wheels in order to preserve geometry and performance
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 evenly distributing the mainspring’s internal tension.
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.
SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE BRIDGES AND CASE
These types of screw permit better control of the torque applied to screws during assembly. These screws are unaffected by physical manipulation during assembly or disassembly and age well.