RM 40-01

Automatic Winding Tourbillon McLaren Speedtail

Based on the form of a teardrop, the most aerodynamically efficient shape found in nature, the Speedtail is the apotheosis of the streamlined hypercar, a three-seat grand tourer that became the third car in McLaren's Utimate line-up.

With its 1,070-horsepower hybrid powertrain, the Speedtail covers 112 metres per second when travelling at its top speed of 250mph/402kph, making it the fastest McLaren road car to date. McLaren's relentless pursuit of aerodynamic efficiency provided the starting point for the design of the RM 40-01 Automatic Tourbillon McLaren Speedtail.

RM 40-01

New technical heights

The RM 40-01 automatic Tourbillon McLaren Speedtail is our most extreme watch matched to the specific design of the fastest road-going car McLaren ever produced.


Rob Melville, McLaren Automotive’s design director, says the RM 40-01 demonstrates beautifully why the two brands make ideal partners. "Richard Mille watches are known as 'racing machines on the wrist', and that's supported by the fact that there are so many similarities in the way we approach a problem, such as saving weight, reducing vibrational impact and minimising resistance. When it came to the RM 40-01, we had considerable input in sharing the highlights of the car and the philosophy behind it. With the Speedtail, we set out to produce a car that had an artistic quality to it. That has certainly come through in the watch, which beautifully mirrors the many various details of the Speedtail in its finish, materials and its uncompromising design.”



Despite the extraordinary anatomy of the case, Salvador Arbona, Richard Mille's Movement Technical Director, created a horological 'engine' that seamlessly occupies all the available space and introduces a level of mechanical sophistication that makes the RM 40-01 an appropriately extraordinary companion to the Speedtail.

Grade 5 titanium has been used for key components such as the bridges, the bridge screws, the baseplate and the rotor core. The CRMT4 calibre that drives the RM 40-01 introduces the first in-house development for a power reserve display as well as the oversize date and function selector complications. All of which are firsts at Richard Mille on an in-house tourbillon.

The entirely new movement architecture demanded a remarkable 8,600 hours of development, much of which went into finalising the extreme level of detail. The complexity of the components, the multitude of details and, above all, the attention applied to the finishes place the RM 40-01 firmly at the peak of Swiss-made watches.


Automatic winding tourbillon movement with hours, minutes, variable-geometry rotor, oversize date, power reserve indicator and function selector.

Limited edition of 106 pieces



Around 50 hours (± 10%), indicated at 9 o’clock and powered by a planetary differential.



The baseplate and the bridges are crafted of 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, aeronautical and automobile industries.

The skeletonised baseplate and the bridges were subjected to separate and extensive validation tests to ensure they met rigorous strength requirements.



This type of balance wheel represents the ultimate in innovation. It guarantees greater reliability when subjected to shocks and during movement assembly or disassembly, hence better chronometric results over time. The regulator index is eliminated, and a more accurate and repeatable calibration is possible thanks to four small, adjustable weights located directly on the balance.


- Oscillating mass in platinum

- Core made of grade 5 titanium

- Weight segment in red gold

- Guide rail in black PVD-treated metal

- Oneway® automatic winding with ceramic ball bearings and inversion system mechanism

- Bidirectional winding system

This variable-geometry rotor makes it possible to adjust the winding function to the owner’s activity level. Adjusting the weight, which can be slid sideways into the correct position and fixed in place by two spline screws, modifies the setting.

The inertia of the movement is optimal when the weight is closer to the external outside edge, and the barrel thus rewinds more quickly. If the weight is positioned at the centre of the rotor, inertia is decreased and the barrel winds more slowly.



- Movement dimensions: 30.48mm x 35.35 mm
- Thickness: 6.81 mm
- Number of jewels: 37
- Balance: CuBe, 4 arms, 4 adjustable weights, moment of inertia of 7.5 mg.cm2, 50° angle of lift
- Frequency: 28,800 vph (4 Hz)
- Balance spring: AK 3
- Shock protection: INCABLOC 908.22.211.100 (transparent)



It took Richard Mille's casing department, led by Technical Director Julien Boillat, an unprecedented 2,800 hours spread over 18 months to perfect the lines. Like the Speedtail on which its based, the watch’s lines mimic the form of a water droplet while bezel indentations evoke the bonnet openings, and pushers that recall the air outlets behind the front wheels.

The RM 40-01 has one of the highest levels of finishing ever executed at Richard Mille. There has been a lot of development with our anglers and polishers. The attention to detail is extreme, with mirror polished, plain and satinised effects in different areas and the combined use of titanium and Carbon TPT®. The case itself is made from 69 individual parts.

Due to the unprecedented complexity of the design, five prototypes were created before the optimum shape was achieved. The challenge lay in the fact that the case is significantly wider at 12 o'clock than at 6 o'clock, with a further taper between the titanium bezel and case back, which are separated by a caseband made from Carbon TPT® and unequal length titanium pillars.


The design and execution of the watch demonstrate a holistic approach to conception of the movement, case and dial.

As a result, everything has been constructed according to extremely rigorous specifications. For example, a casing ring is no longer used, and the movement is mounted on chassis mounting rubbers (ISO SW) fixed by titanium screws.

The bezel and caseback are made of grade 5 titanium whilst the caseband is made of Carbon TPT®. This is a remarkable material with a unique finish obtained by layering hundreds of sheets of carbon fibres using an automated process that changes the orientation of the weft between layers. Heated to 120 °C in an autoclave similar to those used for aeronautic components, the material is then ready to be machined at Richard Mille.

The tripartite case is water resistant to 50 metres ensured by 2 Nitrile O-ring seals. The case is assembled with 12 grade 5 titanium spline screws and abrasion-resistant washers in 316 L stainless steel.



The strap is also a unique design, being asymmetrical and with the rubber version using Vulculor® technology from Biwi SA, a special process that enables coloured rubber to be over-moulded - so allowing the iconic McLaren orange accent coloured stripe seen at 6 o'clock on the movement to extend to the wrist.




- Hand-polished anglage
- Hand-polished stepped bevelling
- Microblasted milled section
- Microblasted sinks
- PVD treatment for the bridges
- Electroplasma treatment for the baseplate

Steel parts

- Satin-finished surfaces
- Hand-polished anglage
- Hand-polished sinks
- Burnished sections


- Diamond-polished sinks
- Circular decorations on the front surfaces
- Rhodium plating (before cutting the teeth)
- Minimal corrections applied to the wheels in order to preserve geometry and performance

Other features

FAST-ROTATING BARREL (5 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.


The entire going train of the watch, the primary transmitter of power throughout the movement, utilises a special profile for the teeth of the wheels, ensuring a 20° pressure angle.

This system equalises any discrepancies that might arise between the centres of each wheel, for instance due to thermal changes and normal use, and promotes the smooth transmission of torque to the balance wheel, thus supporting excellent chronometric results.


This permits better control of the torque applied to screws during assembly.

These screws are unaffected by physical manipulation during assembly or disassembly and age well.

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