December 5, 2022

I would like to get the opinion of the experts regarding AP Calibre 3120? The reason I’m asking is because, from a mere aesthetics standpoint, I find myself drawn to the newer incarnation of the Royal Oak (15400) vs the traditional Jumbo (15202), notwithstanding the latter’s greater faithfulness to the original and the quality/historical significance of calibre 2120 (JLC920). 
I absolutely don’t want to turn this thread into a pros and cons for either Royal Oak. My only concern is to get as enlightened an opinion as possible on the quality, sturdiness, serviceability, and reliability of Calibre 3120. The only objective and detailed information I have been able to obtain regarding it is this 10-year old, very thorough review of the caliber by Suitbert Walter (http://www.p178host.com/apgallery/3120/), which I read as very positive regarding the caliber’s design and construction.
On the other hands, the various forums appear to be littered with comments regarding alleged reliability problems for the 3120, ranging from poor accuracy, problems with the date change mechanism, and just overall lackluster reliability. However, it is very hard for a non-expert like me to determine whether there is any real issue behind those, or whether these comments are just mere repetitions by non-owners of “stuff they’ve read elsewhere”, without actual first-hand experience or data.
I would expect that if there were ever a good place to get “l’heure juste” (pardon the pun) regarding this caliber, it would be here. I’m hoping that either watchmakers or people with significant amounts of experience with the caliber can chime in and give me the real lowdown on Calibre 3120. Real info vs hearsay…
Thanks for enlighting me!
Best regards,

ClaudeI feel my opinions on this topic are well supported, as I have now owned several Caliber 3120 and 3126 powered watches (the 3126 essentially adding the chronograph module to the 3120 base movement) for many years.
Let’s take each of your points to examine:
1. Quality – I have witnessed Caliber 3120 being finished and assembled at the AP Manufacture.  It is nothing short of a canvas for traditional watchmaking.  Hand applied finishing, beveled and polished edges, a beautiful 22 carat gold rotor.  High quality.
2. Sturdiness – I believe this point is one of the key advantages of Caliber 3120.  It is highly robust.  The movement has a double balance bridge and the rotor glides on ceramic ball bearings.  The power reserve is 60 hours.  I personally do not exercise with a watch of any kind on my wrist, but if inclined, I would not hesitate to wear a 3120 based watch while doing so.  It is an easy winding movement with the gold rotor and bidirectional winding.
3. Serviceability – I have been told by AP that the movement is easily serviced by their watchmakers.  I have serviced Caliber 3126 Offshores before, and they have never needed anything beyond new lubrication.  Obviously, AP will have parts for this motor indefinitely.
4. Reliability – again, in my personal ownership experiences, EXCELLENT.  I wore a steel 15300 Royal Oak about a year straight around 2007.  It worked flawlessly.  I owned a gold 15300, and while it was more of a special occasion piece, it too never had an issue.  More recently, my AP Diver  functions perfectly.  I have found 3120 / 3126 based APs to easily perform within 5 seconds / day in terms of accuracy.  Highly acceptable in my opinion.  A security mechanism that blocks the date disc presents piece of mind for not accidentally damaging the movement when making rapid date corrections.  60 hours of power reserve allows you to not wear it for 2 days and it can still be operating.
I would place my personal experiences with these calibers over 8 years up against any random remarks you have come across around the internet.  Has every Caliber 3120 been perfect?  Surely not, but issues are easily addressed and AP stands well behind their products.

This message has been edited by MichaelC on 2015-02-09 10:58:42 I actually wanted to pick up the jumbo 15202 at the Geneva boutique. They had one in RG – I won’t deny it felt nice on the wrist but I was keen on the SS & the SS was on a 90 day waiting. The price difference was there but to me, at the price point, not that much of a consideration. The Sales lady (& kudos to her) suggested I try on the blue 15400. I did say that I pretty much did everything with my watch on – jog, golf, gym et al. She said the 15400 was built like a ‘bull’. The quick change date mechanism was another +1. I tried it & fell in love with it. I also tried the RG Chrono on the 41 mm but to me, it did not talk as well as it looked in pictures. I landed up picking up the blue dial boutique edition & an additional year warranty was provided by the boutique. 
I have been pretty much wearing it for the last 6 months & on your question on the movement, till now flawless, reliable & very, very accurate.
Hope this helps.
Best
MallyI had an issue with my 15400 and the movement. Had been using the watch pretty much over the last 2 years.. the watch suddenly stopped and the began working again… two days before the warranty expires I sent the watch to AP Service Center and the did make a great job.. Otherwise I love the watch, it is really accurate  and AP really stands out for their products GREAT SERVICE… Gave me another year of warranty…