The RM 72-01 Automatic Flyback Chronograph, a masterpiece unique to Richard Mille that challenges conventional wisdom about chronographs.

The RM 72-01 was released as Richard Mille's first in-house chronograph. It may look like an automatic chronograph designed for thinness, but there's more to it than that. What Richard Mille achieved with this model was unprecedented legibility. This was made possible by a unique mechanism called the double swing pinion, a clever idea that uses two swing pinions with horizontal clutches. What emerges from this design is the Richard Mille approach, never bound by conventional wisdom.

Unprecedented double swing pinion provides outstanding visibility

Since its founding in 2001, Richard Mille has been pursuing the "extreme." The world's lightest tourbillon, completely new and different materials, the pursuit of shock resistance, painting of the movement, etc. Although these attempts may seem difficult to understand at first glance, when unpacked under the keyword "extreme," it becomes clear that there is a remarkable consistency to them.

　The RM72-01, released in 2020, is an automatic chronograph with a conventional design. It is not the lightest model like the Nadal, nor is it exceptionally shock-resistant like the Pablo. However, this model is just as extreme as the existing models.

　Richard Mille has given its chronographs a third tri-compax layout. The RM 011's typical chronograph subdials consist of a small seconds, 12-hour and 60-minute counters, and a 60-minute countdown timer. In contrast, the RM 72-01 features a 60-minute counter at 2 o'clock, a 24-hour counter at 5 o'clock, and a small seconds at 9 o'clock. Not only have the three subdials been expanded to the very edge of the dial, but the two subdials indicating the chronograph time have been moved to the right side of the dial. The RM 72-01 offers excellent legibility, as the chronograph time can be checked simply by rolling up your sleeve.

　Since the basic design was established in the 1930s, the layout of mechanical chronographs has not changed significantly. This is because the operation of the levers that operate the chronograph mechanism remains similar. In contrast, Richard Mille has redesigned the clutch that operates the chronograph in order to achieve "extreme legibility."

　Modern chronographs tend to favor a vertical clutch, which takes up more vertical space relative to the movement but saves horizontal space. The RM72-01, on the other hand, opts for a classic horizontal clutch, specifically a swinging pinion. This mechanism, once considered "cheap," is used in models like the ETA7750. However, because it allows for a lighter clutch, it's ideal for flyback watches. In recent years, IWC has perfected excellent flyback chronographs by focusing on swinging pinions, and the RM72-01 could be said to further advance this approach.

　A normal swing pinion connects a pinion to the fourth wheel, which rotates once per minute, to turn the central seconds chronograph wheel. In the RM72-01, the gear of the 60-minute counter at the 2 o'clock position is driven from the barrel via an auxiliary gear and swing pinion. Theoretically, a swing pinion, with its lightweight clutch, is less likely to malfunction even when operating the flyback. Additionally, the RM72-01 uses two swing pinions to make the clutch smaller, freeing up space for the minute counter at the 2 o'clock position.

　Designer Salvador Arbona points out another benefit of the double swing pinion: "In a typical chronograph, the seconds chronograph wheel directly drives the minute totalizer wheel, which requires a considerable amount of energy per minute." Indeed, by using a double swing pinion, the seconds chronograph wheel receives torque from the fourth wheel and the minute totalizer wheel receives torque separately from the barrel, so the torque loss will be smaller. It's no wonder that Richard Mille describes this as "a chronograph that delivers the best performance in both power reserve and isochronism."

　Usually, when designing their first in-house chronograph, many manufacturers like to play it safe. However, Richard Mille chose to use a swing pinion instead of the standard vertical clutch or horizontal clutch with a carrying arm. Some discerning watch enthusiasts might say, "It's just a swing pinion." However, what was important to Richard Mille was not public opinion, but "extreme legibility." This is a model worthy of Richard Mille's first in-house chronograph.