I'm glad
red1 is lending some support to my concerns: the factories will have to invest some ingenuity to get right the new 15500 datewheel alignment, harder than any previous RO reference (the notorious ROO date window gap is not being discussed here). Here's why:
1. AP cal 3120 diameter: 26.60mm;
2. ETA cal 2824-2 & 2836-2 diameter: 25.60mm;
3. Miyota 9015 diameter: 25.60mm;
4. Patek cal 324SC diameter: 27.00mm;
5. ETA 2894-2 diameter: 28.00mm;
6. ETA 7750 diameter: 30mm;
7. AP new cal 4320: 32mm.
Now, we don't have to be engineers to start contemplating that JF (or any other factory for that matter) will have to start producing grand datewheels that will have the square footage of half a dial
As
BIONONE has rightly pointed out it's anyone guess what issues a datewheel overlay of this size can cause.
So while it seems an easy task to replicate the new 15500 I'd think that AP had something in mind when developing the new calibre. Probably they just had enough of JF's 15400s and 15703s and decided to change tack. It's been relatively easy for the factories to replicate the date window position of the AP refs using cal 3120 or PP using cal 324, but this new calibre is 5+mm bigger in diameter so that's not something we should overlook. I don't think it's too much too early to suggest that the factories will start looking at the good old 7750 as a base for the 15500 model. It beats at the same rate and is nearly as good looking