May 23, 2024

I understand from the Internet that RO15202 watch with the 2121 movement has, like all JLC 920-based movements, an issue with mainspring barrel bridge suffering wear when the pivot structure of the mainspring isn’t well maintained and side shake produces wear on the barrel bridge. The outcome being that the whole barrel bridge must be replaced.  Is this true?

I see that AP implemented a different movement for the 15400. Cal 3120 I think.   Does that movement have the same issue? 
Which is the most robust of all the RO movements. 
Many thanksThe 2121 has been used for years and years.   All watch movements are intended to be serviced at regular intervals (3-5 years typically, depending upon your use).  Do that according to AP and you won’t have a problem.
The use of the 3120 in the 15400 has absolutely zero to do with anything related to the 2121.  The 3120 is primarily an issue free movement, a very solid and robust caliber.
I have owned various APs since 2001, including several 3120s / 3126s, and my 2121 powered 15202 for almost 2 years.  Never had a single issue with any of them.