A7750 in non-chrono watches

[Aramis2288 6,271]

So I decided to open a can of worms and kick-off another (but perhaps not too obvious) A7750 discussion.

Before I start, a small disclaimer:

I am aware that there is an infinity of information about A7750 on all rep forums. I know it's quite a controversial movement, can be a hit-or-miss kind of thing and it's highly advisable to get it serviced straight OOTB. I realise that a significant number of issues with it is related to watches with chrono and (depending on the placement of the sub-dials) it may fail very quickly due to the additional strain caused by extra gears and lack of bearings/rubies on them. The question I want to ask, however, is a bit different and despite doing rather extensive research on RWI/RWG I've not happened to find a thread providing me with satisfactory information. IF by any chance there is a robust source of answers to my question which I may have missed, feel free to point it out - I will be more than grateful.

 

 

Having stated that, let's jump straight to it - A7750 in non-chrono watches - how reliable/unreliable is it, comparing to its applications in reps equipped with a chronograph?

Let's take the ZF and XF PAM 1389 rep as an example:

https://www.intime05.co/panerai/4174-pam-1389-titanium-zf-best-edition-black-ceramic-bezel-black-dial-on-black-rubber-strap-p9010.html

https://chazingtime08.co/products/pam1389-titanium-xf-best-edition-black-ceramic-bezel-black-dial-black-rubber-strap-p9010

Not sure whether these are still achievable, but as you can see, in this application you have the A7750 kept in its most basic form. The only complications there, are time and date. My common-sense assumption would be that since probably the strain on the movement is significantly lower than compared to e.g. Breitling Navitimer reps, its reliability and longevity should in result be increased.

 

• Given the fact that the movement itself, and specifically its later iterations are probably not as bad as it used to be initially and having taken all of the issues related to the chronograph out of the equation, is it any more reliable in a simplified application with only date/time complications on the watch?
• Do you have any experience with PAM 1389 (or any other rep) running the 'simplified' A7750 which you can share? 
• Can the A7750 movement in such an application be replaced with Swiss ETA 7750 without modding?
• Do you think that P.9001/P.9000 clone movement (used e.g. on VSF PAM 683)  is more reliable?

[GenTLe 1,509]

I've serviced a couple of these non chrono 7750, so I can tell something about them.

Basically: the care you should take about manual winding is still there, the mechanism is absolutely the same as the chrono version.

Also the problem that sometimes happen with the reversing wheel on auto winding system (watch that stops to autowind all together -reversing wheel stuck open- or makes the counterweight to rotate when you manual wind -reversing wheel stuck closed-) is also there, but that's much easier to take care of it (removing the reversing wheel to clean it an reassemble it is MUCH easier than on those with the chrono functions, tilting pinion and so on).

About the rest (bent chrono levers basically) is of course away.

So I'd not call them "workhorses" but moderately ok. In the end they're not much different from the chrono 6/9/12 configured A7750.

About replacing with 7750: well, you definitively need to strip away all the chrono functions from that one, and probably the small second hand will fit loose (or not fit, I can't remember now if it's in excess or defect, bit I kind of remember there's 0.04 / 0.05mm difference in pinions size on the small hands between the A7750 and the 7750).

I've no idea about the clone movements, so can't voice for them.

[Aramis2288 6,271]

13 minutes ago, GenTLe said:

About replacing with 7750: well, you definitively need to strip away all the chrono functions from that one

So say that this kind of non-chrono A7750 movement gives up completely, it seems like the most headache-free option to get the watch back on track would just swapping it with new A7750 movement.

Based on your statement above I understand that obviously, this kind of new OOTB A7750 would still require some work on stripping away all the chrono functions, correct?

 

[GenTLe 1,509]

1 hour ago, Aramis2288 said:

So say that this kind of non-chrono A7750 movement gives up completely, it seems like the most headache-free option to get the watch back on track would just swapping it with new A7750 movement.

Based on your statement above I understand that obviously, this kind of new OOTB A7750 would still require some work on stripping away all the chrono functions, correct?

 

Yes definitively (to both the statements). But, considering that, I'd go for servicing the 1st one (as also the new one would require servicing anyway) and using the parts from the 2nd to fix the 1st.

Note that the non chrono GMT version is also different (the top calendar plate is different and there are more parts under the dial. But you can get it "as it is" here: https://www.aliexpress.com/item/4001083832509.html (and this can be turned into a chrono by adding the needed parts)

[Aramis2288 6,271]

51 minutes ago, GenTLe said:

But, considering that, I'd go for servicing the 1st one (as also the new one would require servicing anyway) and using the parts from the 2nd to fix the 1st.

Good idea.

Btw, by any chance, do you know whether A7750 in more 'classic' applications (such as Breitling Navitimer, Omega Speedmaster or other watches with the seconds subdial @9), is it swappable 1-1 without a need to perform any surgeries?

[GenTLe 1,509]

6 minutes ago, Aramis2288 said:

Good idea.

Btw, by any chance, do you know whether A7750 in more 'classic' applications (such as Breitling Navitimer, Omega Speedmaster or other watches with the seconds subdial @9), is it swappable 1-1 without a need to perform any surgeries?

Also in those applications still the problem of different hand pinion sizes is present. I know many did the swap, but I can't really say how they managed to have the hands firmly in place (unless replacing them with gen ones). Plus don't think that gen 7750 are so much better than the asian counterpart...

[tribefan 6,768]

On 25/10/2020 at 13:02, GenTLe said:

Also in those applications still the problem of different hand pinion sizes is present. I know many did the swap, but I can't really say how they managed to have the hands firmly in place (unless replacing them with gen ones). Plus don't think that gen 7750 are so much better than the asian counterpart...

Any issue with dial swaps? Are the hand spacing and date wheel an issue if I want to swap a rep with gen on an A7750? Sounds like if I use the same hands, I'm good. 

[GenTLe 1,509]

The 2 movements are clones. The differences are in minuscule details like the pinion diameters and so on. Dial, spacing, stem position and size... That's all the same.