n the eighteenth century, a golden age for advances in chronometry, Abraham-Louis Breguet was one of the first watchmakers to study ways to reduce energy loss in the escapement. His natural escapement, which had two escape wheels, was designed to reduce friction and make the movement more efficient. Breguet’s system was a considerable step forward, but still required a relatively large amount of mainspring energy because of the many wheels needed for it to function.

In 1865 German watchmaker Charles Fasoldt registered a patent for what can be considered the first “co-axial” escapement. At the heart of Fasoldt’s design were two escape wheels, mounted on the same axis. However, the most remarkable innovation was a three-pallet lever that limited energy loss caused by friction.

These advances would later inspire the British watchmaker George Daniels, who devoted much of his lifetime to perfecting the co-axial escapement. His aim was twofold: do away with the energy-hungry phases that are inherent to a traditional lever escapement, in particular locking, unlocking and impulse, and most of all eliminate sliding friction. By replacing sliding friction with radial impulses, Daniels’ escapement required significantly less lubricant for the pallets (lubricants deteriorate over time, which contributes to a gradual decrease in precision).

Developed in the 1970s and patented in 1980, the co-axial escapement proved difficult to manufacture at industrial scale—until the late 1990s when Nicolas G. Hayek decided to put Swatch Group’s manufacturing might behind the project and integrate co-axial escapements into Omega SA movements.

In 1999 the brand launched Calibre 2500, the first series movement with a co-axial escapement. It equipped, among others, the Constellation collection. Despite Daniels’ initial reservations about high frequencies, Calibre 2500 ran at 28,800 vibrations/hour (a frequency that was subsequently slightly reduced for better reliability). The movement’s increased efficiency allowed for longer service intervals and more stable precision over time. A marketing dream.

Introduction of the silicon balance spring

A second pivotal moment came in 2008, when Swatch Group fitted a silicon balance spring into a movement designed around the co-axial escapement.

Silicon would be a milestone in progress towards ever more stable timekeeping, thanks to properties that are of particular benefit in a regulating organ. Silicon is non-magnetic, extremely lightweight and, because of its very low thermal dilation coefficient, virtually unaffected by fluctuations in temperature. Chemical treatments have significantly improved its resistance to shocks and shock-induced deformation, while its natural thermal stability ensures consistent chronometry over a longer period.

The regulating organ thus gains in both efficiency and rate stability. This combination of a silicon balance spring with a co-axial escapement results in much higher levels of chronometric performance for Omega SA’s movements, while improving overall reliability.

New standards for chronometer certification

Watches manufactured by Omega SA are delivered with two certifications: that of the Contrôle Officiel Suisse des Chronomètres (COSC) and Master Chronometer certification, issued by the Swiss Federal Institute of Metrology (METAS).

The Speedmaster Super Racing, fitted with Calibre 9920, became the first watch to incorporate the Spirate System that debuted in January 2023. This new technology features a balance wheel whose silicon balance spring allows ultra-fine regulation.

Traditionally, COSC chronometer certification has required an average rate of between −4 and +6 seconds/day (a delta of ten seconds). In February 2026, the organisation introduced the stricter COSC Excellence Chronometer certification, which reduces tolerances to between −2 and +4 seconds/day (a delta of six seconds).

METAS sets an even higher bar for its Master Chronometer certification. Precision must fall within a range of 0 to +5 seconds/day (no negative value). Watches are submitted to additional tests in conditions that simulate real-world wear, including resistance to magnetic fields and verifying the stated power reserve.

The Speedmaster Super Racing pushes to an even higher level, with certified precision of between 0 and 2 seconds/day (an average of one second in absolute value).

In practical terms, precision will always depend on conditions of use and the wearer’s wrist movements. Even so, collectors generally prefer a watch that runs slightly fast rather than slow, and will therefore appreciate the absence of a negative value.

At between -2 and +2 seconds/day, despite a delta of four, Rolex’s latest tolerances have a theoretical average of zero.

The Spirate System

In a traditional movement with an index, precision is regulated by adjusting the active length of the balance spring. The flat blade of the spring passes between two pins. The spring’s beat between these pins defines the frequency, which is adjusted by moving the pins to lengthen or shorten the spring.

Rather than change the active length of the balance spring, the Spirate System adjusts its stiffness. The silicon balance spring, which is manufactured by Deep Reactive Ion Etching (DRIE) to limit its sensitivity to physical constraints, ends at a flexible blade. Micrometric adjustments to the stiffness of this blade fine-tune the watch’s rate by plus or minus 5 seconds, in increments of 0.1 second. Adjustments are made by rotating a special screw, above a snail cam. A further advantage of the Spirate System is that these adjustments can be made in-store by a watchmaker.

Chronometry and industrial production

Positioned in the so-called “affordable luxury” segment, the Speedmaster Super Racing illustrates Omega SA’s capacity to fuse top-quality industrial production with advanced innovations, while meeting the exacting standards of COSC and METAS certification. Through the combination of a co-axial escapement, silicon balance spring and the Spirate System, it pushes the boundaries of the precision that can be achieved by a contemporary mechanical watch.