What would affect daily accuracy? UPDATE

Archer

The co-axial escapement by itself does not add any shock resistance. There are other features on the newer watches (8500 and 9300 based watches) that would have some value in terms of shock resistance, but only if you are referring to it in terms of affecting accuracy of the movement, rather than damage.

Modern watches all have shock protection on the balance staff pivots, so regardless if it is regular Incabloc, Kif, or the new system that Omega is using, I don't think there is any significant difference in how those systems protect the staff from breaking during a shock. If there was, Omega would be screaming t from the mountain tops at every opportunity. So the likelihood of having a broken staff from dropping the watch for example, is probably about equal with all those systems with all else being equal (mass of the balance, diameter of pivots, hardness of pivots, etc.)

What is an advantage on the newest movements is the free sprung silicon balance spring. First off, a free sprung balance does not have a regulator that can move with a shock, so in order to affect the accuracy it takes a shock big enough to distort the balance spring. Since balance springs have little mass, that means it takes a large shock to distort them. Second is the silicon material the spring is made of the in latest watches. When I was at Omega for training on co-axial watches, they showed us the silicon spring just by itself. As they passed it around the room, we were encouraged to grab onto the stud of the spring with our tweezers, and pull the spring straight up, until we stretched into basically a straight line shape. I did that, and then let it back down, and the spring returned to it's previous shape - a metallic balance spring would not fare well at all doing this test...it would be permanently and severely deformed.

So the spring is much less likely to go out of shape, both in actual use, and when being worked on. I see many remarks about the incredible accuracy of the newest "co-axial" movements, but that accuracy really has little to do with the escapement - it comes from that silicon spring. If you were to use that same balance spring technology on a traditional Swiss lever escapement watch, you would get the same results...

Hope this helps.

Cheers, Al

Archer

I haven't gone through all the variations to see what has silicon and what doesn't, but off the top of my head none of the 2500's or the 3313 have the silicon spring - they have metallic balance springs, but they are free sprung so no regulator. The 3330, and the later versions of the 8500 family have the silicon spring (originally the 8500 didn't have it), and the 9300's have it.

And yes, I would say this spring has the biggest impact on accuracy - to be able to serially produce basically perfect balance springs, and have them maintain their shape is a big thing in terms of producing consistent accuracy. They still have to be regulated, and if improperly done this can cause poising errors, but these springs are the main source of the consistent accuracy you see. That's not to say a regular old Swiss lever with a regulator on it can't be as accurate, just that it takes more work/skill to get there.

Wear and tear - that's a whole other subject. Omega stated quite clearly in the training I attended that the sole purpose of the co-axial escapement was to extend service intervals. Those extended service interval claims started out much longer than they ended up. The claims made are questionable in my experience. The escapement is just one part of a larger groups of parts with many lubrication points that form the watch movement, and I can tell you that I rarely get watches in for service that the only problem with them is the escapement lubrication...so does eliminating* lubrication there really make a significant difference? What about the rest of the movement? You don't have to be a watchmaker to figure out the answers...

Cheers, Al

* - lubrication still required on the co-axial - not for friction but it acts as a cushion to protect the co-axial wheel from getting chewed up like this: