Greetings,
Recently someone on another watch discussion site reported on discussions he had with two IWC watchmakers. In essence they told him "chronos are meant to be used; there's nothing wrong with running a chono all the time. No harm will arise." He reported his informal interviews as if they were "official" pronouncements from IWC, which of course they are not. People thanked this person for getting a final pronouncement on this subject.
I don't buy it. Here's what I wrote in reply:
[i]
I respectfully disagree, at least in part
With respect, I don't care if a person is a watchmaker or if that person gets a paycheck from IWC (as do I). In fact, the person who replied to you really cannot speak officially for IWC. Perhaps you can ask to contact me to discuss the issues; I will separately raise the matter with IWC executives.
That said, I will discuss briefly the issues inolved. First, a chronograph is actually very simple in concept: it is basically an additional seconds hand, with (a) the addition of a mechanical start/stop mechanism and (b) a series of totalizers. Running a seconds hand does not require a lot of power, for sure, and in that sense there is little effect on the watch. In that sense, what you were told is true.
However, the use of the chronograph does reduce the movement's amplitude somewhat. It varies from watch to watch, but I'd guess the reduction is such that a typical watch, with a chrono running all day, will run about 20/seconds a day slower. That doesn't bother most people, and isn't considered serious, but there IS an effect on "accuracy" and that does bother some people.
Next, there are various ways that some chronos are designed to avoid loss of amplitude on running. The "in' way today is to use a vertical clutch design (and without going into details you can Google to learn about that). A slightly different approach was used also for the new Da Vinci chrono, again to improve performance when the chrono is running by eliminating ampliutude variances. However, these approaches are not used in the Valjoux based chronos that IWC uses, which is most models. It's again not serious, but movement designers do recognize that there is an issue and there are designs to deal with that.
Next is the issue of wear. Some people consider additional running of functions as nominal, while others believe that all running increases wear and decreases service time. You had one watchmaker who said to have the watch serviced every two years --absurb advice, contrary to IWC's own printed recommendations and very costly. Perhaps it doesn't matter to him. But I will tell you that Patek Philippe in its booklets (or at least some Ive read --I can't check all) accompanying its chronos state that they do NOT recommend running a chronograph constantly. I'm not sure what an IWC watchmakers knows that Patek does not, or vice versa. But the IWC chrono design is no better in this respect than Patek's, and I think it shows that there is a legitimate disagreement among professionals.
So, if you don't mind your watch being more "off" in timekeeping, and if you don't mind the possibility of a somewhat shorter service interval, continuously running the chrono really isn't an issue. No great harm will arise. But with respect I don't care who you talked to at IWC --that doesn't change the facts.
Regards,
Michael Friedberg
(this also isn't an official position by IWC)
Your thoughts here are welcome.
Regards,
Michael
