Following up caliber 4030 was Rolex’s in-house caliber 4130 chronograph in 2000. In 2023, the caliber 4131 replaced the 4130.
The new movement caliber 4131, now features Rolex’s patented Chronergy escapement and a chronograph mechanism that uses fewer components, thus enhancing energy usage and reliability. The movement beats at the same 4Hz frequency and has the same 72-hour power reserve as before. The rotor which winds the mainspring bidirectionally and has been redesigned though with a skeletonized cut-out, with one version made of nonprecious metal for the standard Daytonas, and on the 126500LN platinum model, it’s made of 18K yellow gold, and visible through the open caseback.
The bridges of caliber 4131 now feature Rolex Côtes de Genève decoration, versus the traditional Côtes de Genève. A slightly polished groove between each band makes the otherwise ubiquitous finish more exclusive to Rolex. And while you do not see this on any Daytona except the platinum model, as mentioned above, Rolex could add the sapphire casebacks to more models in the near future.
Considering the power reserve has remained the same, the free-sprung balance system has remained the same, the Superlative accuracy of -2/+2 (cased up) is the same, the smooth actuating column-wheel with no jump or power loss vertical clutch is the same — apart from the new decorations and rotor — perhaps the biggest change from a technical standpoint is the reduction of components.
From the circa 1988 caliber 4030 (Zenith designed) used in the Daytona 16520 and 116520 references, to the circa 2000 caliber 4130 used in the 116500LN (Rolex designed), Rolex reduced the number of movement components, and now with the circa 2023 caliber 4131 (Rolex designed) that powers the 126500LN, they’ve reduced the number of components again, while maintaining all the existing features and upgrades. This means the caliber 4131 will, theoretically, be more reliable and require fewer parts to service than previous calibers.
Caliber: 4131
Release Date: 2023
Country: Swiss made
Type: Automatic
Dimensions:
Total Components:
Jewels: 47
Oscillating Frequency: 4Hz (28,800 VPH)
Power Reserve: 72 hours
Functions: Hours, minutes, small seconds, chronograph (12-hour elapsed time limit)
Balance Wheel: Variable inertia, free-sprung
Rotor: skeletonized, bi-directional winding
Finishing: Rolex Côtes de Genève, faux gold chatons
Unique Features: Traversing bridges
