Richard Mille "RM 27-04 Tourbillon Rafael Nadal": The correlation between lightness and strength

2020 marks the 10th anniversary of the start of the "co-development" between Richard Mille and Rafael Nadal. The extremely lightweight Extreme Watch, described as "Nadal's other skin," even sparked a paradigm shift in the notion of lightness as a new luxury. However, Nadal's latest model goes beyond its overwhelming lightness and instead seeks strength.

RICHARD MILLE TECH 2020
[RM 27-04 TOURBILLON RAFAEL NADAL]

　The G-value, which indicates the magnitude of an impact, is closely related to its weight. Damage to an object is calculated by multiplying its weight by the impact value (G-value). Generally speaking, the stronger the watch, the heavier it is, resulting in greater damage. Since its debut, Richard Mille has continued to create "Extreme Tourbillon" watches using a variety of approaches. For example, the polo player Pablo Mac Donough model was an attempt to increase direct impact resistance, while the tennis player Rafael Nadal model was an attempt to create a lightweight watch. However, in reality, these two are two sides of the same coin, and while they share advanced technology, they have evolved separately. The latest evolution of this is the eighth Nadal model, the "RM27-04 Tourbillon Rafael Nadal."

　The first attempt at a "cable suspension system," in which the movement is suspended by wires, was the RM27-01 Tourbillon Rafael Nadal, released in 2013. However, subsequent Nadal models did not incorporate cable suspension until the RM56-02 Tourbillon Sapphire in 14, followed by the second MacDonough model, the RM53-01 Tourbillon Pablo MacDonough, in 18, marked a major evolution. While the RM27-01 and RM56-02 had a floating mount for the movement using only planar tension, the RM53-01's cable suspension was revised to a three-dimensional wire arrangement, similar to that of a cable-stayed bridge. The new RM27-04 system retains this complex design theory while returning to a flat configuration. At first glance, it may appear to be a direct design of a tennis racket, but in order to incorporate the same principles as stringing into the movement, the cable suspension technology cultivated through the development of the RM53-01 was required.

　When developing the first Nadal model, the RM 027 (2010), the development goal was undoubtedly lightness. The prototype weighed approximately 20g including the strap. However, since the RM27-01, which first adopted cable suspension, the focus has shifted from lightness to high impact resistance. The previous model, the RM27-03 (2018), which featured a caseband and baseplate molded as a single unit using Carbon TPT®, finally achieved an impact resistance of 10,000g. The new RM27-04 breaks this record, reaching 12,000g. At approximately 30g including the strap, it's by no means lighter than previous Nadal models; in fact, it's about 10g heavier. Even so, the improved impact resistance is a testament to how much the cable suspension's performance has improved.

　The RM27-04's cable suspension is positioned exactly where the dial would be. A 0.27mm diameter braided steel cable passes through the inner bezel, made of grade 5 titanium, which serves as the outer frame of the movement, and the baseplate is suspended from it. The cable is threaded in the same way as a single string in a tennis racket, with two knots. The cable is actually secured in place by two tensioners made of PVD-treated 5N gold. The total length of the cable, which is threaded 38 times through the inner bezel, is 569mm, and by braiding it vertically and horizontally, it forms an area of ​​855mm2. The movement is suspended along the direction of the cable's grain, so the barrel is at 1 o'clock and the carriage is at 7 o'clock. This configuration resembles a typical tourbillon gear train, but arranged diagonally.

　An interesting feature is the unique shock-resistant device woven into the cable. Pipe-shaped chatons are installed at three points on the movement—the barrel axle, the second axle, and the carriage center—and supported by red shock-resistant devices. This also aids in centering the movement when it's suspended on the cable suspension. The total weight of the movement that can be supported is just 3.4g. The case itself, the "other skin" of the new Nadal, also incorporates a unique material. "TitaCarb®," developed by Richard Mille in collaboration with Swiss company BiWi, is a type of high-performance polyamide. While confusingly, this is an engineering plastic similar to nylon and Kevlar, trademarks of the French company DuPont, and is unrelated to the metal titanium. However, the 38.5% carbon fiber content gives it a tensile strength of approximately 370 MPa (approximately 3700 kg/cm2), making it one of the most durable polymers. Other features include the rigidity of the case, its low coefficient of thermal expansion, and its excellent resistance to temperature and humidity, all of which make it ideal for the Extreme Tourbillon, which can withstand Nadal's intense playing style.

　2020 marks the 10th anniversary of the partnership between Rafael Nadal and Richard Mille. Richard Mille once established a paradigm shift in the concept of luxury, where ultra-lightweight watches were the new standard. Now, the Nadal model, which was at the forefront of this movement, is once again pursuing strength.