RM 55-01
AN ODE TO WEIGHTLESSNESS
At Richard Mille, there are certain models that find their sweet spot in extreme understatement, focalising all the technicity of contemporary haute horlogerie into an architecture stripped down to absolute mechanical necessity. The new RM 55-01 Manual Winding fully ascribes to this approach, projecting a resolutely airy structure where each component is perfectly situated according to its function.
CALIBRE RMUL4
Manual winding skeletonised movement with hours, minutes and seconds.
POWER RESERVE
Around 55 hours (± 10%).
BASEPLATE AND BRIDGES MADE OF GRADE 5 TITANIUM
The calibre rests on a baseplate made of grade 5 titanium, an alloy borrowed from the aerospace industry and highly prized at Richard Mille. To enhance its aesthetics, the baseplate is microblasted, sanded and treated with a black PVD coating. The going train is affixed by three bridges also produced from grade 5 titanium sanded and treated with Titalyt®.
Nonetheless, working this material remains a constant challenge. Milling grade 5 titanium is a herculean task: its extreme hardness and the brand’s low tolerance for error take a toll on every tool. The same uncompromising standards hold for the slightly thicker satin-brushed parts that structure the movement and highlight a tension between straight lines and curves.
FREE-SPRUNG BALANCE WITH VARIABLE INERTIA
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.
DOUBLE-BARREL SYSTEM
The double-barrel system helps to improve the torque stability over a longer period. This is achieved by distributing the stored energy across two winding barrels instead of one, which increases the number of rotations and reduces pressure on the teeth, bearings and pivots, resulting in better long-term performance.
MOVEMENT CHARACTERISTICS
Movement dimensions: 31.25 x 29.45 mm
Thickness: 3.46 mm
Number of jewels: 26
Barrel arbour: AP 20 steel
Balance: Glucydur®, 4 arms, inertia moment 4.8 mg•cm2, angle of lift 53º
Frequency: 28,800 vph (4 Hz)
Balance spring: elinvar by Nivarox®
Index assembly: Triovis N° 2
Shock protection: Incabloc 908.22.211.100 (transparent)
Escapement wheel jewels: Rubifix (transparent)
Two-position stem: Manual winding, hand setting
CASE IN CARBON TPT® AND QUARTZ TPT®
These materials are exclusive materials to the brand in watchmaking with a unique appearance. Their remarkable damascene surface displays extremely regular yet totally unique striations, as they are composed of multiple layers of parallel filaments obtained by dividing carbon fibres or silica threads.
Quartz TPT® fibres are generally used for very high-performance applications due to their resistance to high temperatures, their strength and their transparency to electromagnetic waves. Fibres are aligned in layers no thicker than 45 microns and saturated in resins developed specially for Richard Mille. These layers are then stacked using an automatic positioning system that changes the orientation of the fibre between each layer by 45°.
After being heated to 120°C and subjected to a pressure of 6 bars, they are machined on a CNC machine at Richard Mille’s manufacturing facilities.
Carbon TPT® is made by an identical process, but from carbon fibers threads.
The materials’ unfinished damascene effect harmonises with the taut, clean lines of the three-part tonneau case. The calibre is securely anchored by four spline screws in microblasted titanium, framed with satin-finished pillars and polished bezels. The microblasted and rhodium-plated hands glide above a complex four-part flange that weaves together titanium, carbon fibre, and steel in a play of texture and relief.
Finishing
Movement
• Baseplate and bridges in grade 5 titanium, wet sandblasted, PVD-coated with a straight-line grain finish after coating and Titalyt® treatment for the bridges
• Hand-polished angles
Steel parts
• Screw slot and screws bevelled and polished with rounded and polished tip
• Straight line grain finish of the upper surfaces
• microblasted lower surfaces
• Hand-polished surfaces
• Hand-polished angles
Wheels
• Concave chamfering with a diamond tool
• Diamond-polished angles
• Circular-finished faces
• Rhodium plating (before cutting the teeth)
Other features
SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE BRIDGES AND CASE
This permits better control of the torque applied to the screws during assembly. These screws are therefore unaffected by physical manipulation during assembly or disassembly and age well.
FLANGES
Upper flange: In grade 5 titanium; index points filled with approved luminous material.
Lower flanges: In polyamid and 316L stainless steel.
CRYSTAL
Bezel side
- In sapphire (1800 Vickers) with anti-glare treatment (2 sides).
- Thickness: 1.00 mm minimum.
Caseback
- In sapphire (1,800 Vickers) with anti-glare coating (2 sides).
- Thickness: 1.55 mm at the centre; outer edges 2.29 mm.