How does Clean factory's use of the Shanghai 4131 movement compare to the genuine one? Is it better than the Dandong 4130 movement?

Firstly, by examining the genuine product, we can understand that the latest Daytona models from Rolex, starting with the 1265 series, are updated versions of the Daytona style, also improving upon the models starting with the 1165 series. Besides changes and modifications in appearance, the upgrade of the movement is crucial. The transition from the 4130 movement to the 4131 movement (with perforated rotor, enhanced escapement system, and additional shock absorbers) highlights two key points regarding the genuine movement: firstly, the upgrade from the 4130 movement to the new movement demonstrates the excellence of the original 4130 movement; secondly, there are no changes in the power reserve and functionalities between the 4131 and 4130 movements.

The Shanghai 4130 movement is currently used by manufacturers such as APS Factory, ZF Factory, and some other manufacturers without the copyright to use the Dandong 4130 movement. Most watch enthusiasts who purchase high-quality replica Daytonas primarily choose Clean Factory, which typically utilizes the Dandong 4130 movement. From N Factory to the defunct N Factory and now continuing with C Factory, BT Factory, and the new N Factory, the main advantage of choosing Clean Factory lies in its movement and attention to detail. Concerning the Clean Factory's Daytona with the 4131 movement, which is produced by the Shanghai factory, it's inevitable. We can understand that currently, this Shanghai 4131 movement is nominally a collaborative creation, but in reality, from the movement's polishing, plating, engraving, polishing, and various other aspects, it is independently completed by C Factory.

In terms of quality requirements, C Factory tends to be more stringent. After all, C Factory's Daytona, which is the best-selling model in the replica market, naturally wouldn't want to sabotage its own success. Additionally, C Factory has announced that their Daytona with the Shanghai 4131 movement has a power reserve of 75 hours, compared to the genuine product which still maintains a 72-hour power reserve. However, it's important to note that all watch enthusiasts still have a 72-hour power reserve, and any claims regarding the 75-hour power reserve need to be substantiated through actual testing. Furthermore, it's unrealistic to expect every movement to achieve precisely 75 hours, but even a difference of a few hours can be considered acceptable. Currently, both the Dandong and Shanghai 4130 movements have power reserves of around 68 to 72 hours, which is quite impressive for replica movements.

rom the actual photos, we can see that the left side shows the genuine Rolex 4131 movement, while the right side shows the Shanghai 4131 movement. Comparing the entire structure, it's approximately 98% faithful to the original. The polishing of the balance wheel and the polishing angle of the bottom of the movement are delicate, resembling the details of the genuine movement. We won't delve too much into the small and intricate components, as they are too complex to discuss in detail. Just by looking at the surface part, we can compare the positions of the balance wheel and the engraved scales on the skeletonized bridge. The "Daytona" engraving on the bridge axis is clear and neat, while the scales on the "CHRONOMETER" and "PERPETUAL" parts may not be as clear. It's worth mentioning that although most of the Daytona models in the 1265 series have closed bottoms, there are some differences.

Left: Genuine Rolex 4131 Movement - Right: Shanghai 4131 Movement