Vintage watch service -- SF bay area

Another +1 for Son at World Time in San Jose. I just picked up two watches today, a 145.012 and a Breitling Navitimer 809. I can't say that he offers a bargain, and I'm not an expert, but he appears extremely detail oriented, he sends you photos of your watch completely disassembled, and the finished product looks fantastic (check out the before and after photos of the Navitimer).

However, re: timekeeping parameters, is it normal to still have a minor amount of beat error (0.3-0.8, down from 1.7-2.5 pre-service), and to still have +-20+ sec/day in positions 5+?

The beat error tolerance is typically anything less than 0.8 ms for most brands, so that's not alarming. But is the top slip for the Breitling, and the bottom for the Speedmaster? I will assume that for now...

The Breitling's slip has the lift angle set for 50 degree, and all the information I have is that it should be 53. Not a huge issue, but something to keep in mind as this will affect the balance amplitudes displayed. In this case the amplitudes are slightly understated, and since the dial up and down amplitudes are already quite high, there is possibly a danger of rebanking. The Delta is 27.3 seconds, and although that's not great, it's not horrible for a vintage movement like this. The gap between the two horizontal positions and the vertical is quite large - my first order of business on this error would be looking at the spacing of the regulating pins - closing them up slightly would likely improve this.

On the Speedmaster, the Delta could be a lot better. The Delta is within Omega tolerances, but those tolerances are very wide.

If that bottom slip is for the Cal. 321 Speedmaster, then the bigger issue is that the watchmaker has the lift angle set for 49 degrees. That would be close for a Cal. 861 (which is 50 degrees), but it is 9 degrees too high for the 321, which is actually 40 degrees. So if that is for the 321 Speedmaster, the balance amplitudes shown are very much inflated, and they are most likely much lower than the timing slip indicates. Considering that the rule of thumb is that for every 1 degree off the lift angle is, the amplitude will be off by about 6 degrees, all the balance amplitudes shown would be around 54 degrees lower than what is printed, meaning that they are quite low for a freshly serviced movement. Not sure if this was just an error on the part of the watchmaker, but those results don't reflect the true state of the movement.

Wow, thanks for that reply! But the top slip in my previous post is actually for the Speedmaster before the service, and the bottom is for after. Sorry for the misdirection, it was late last night! Here are the before and after slips for the Navitimer. Do you have any additional comments with this information?

Okay, so then the amplitudes are worse after service, and the Delta is worse...

The watchmakers is using 2 different lift angles for the same watch.


Again, 2 different lift angles for the same watch. After service, the dial up and dial down balance amplitudes are low, but at least the Delta is better.

Overall it's all just very strange...

Hm indeed. I didn't have the before slips when I picked them up, so now I think I will ask him about them next time and see what he says...

PS @Archer what are the tolerances for the 321 and Venus 178 movements?

And is it reasonable that this watchmaker said, in reference to the worse performance in the 5th position for the Omega, that it is typical to only regulate it to 4 positions?

The Venus I have no information on official tolerances. Those would be from Breitling actually, what they require the movement to be within.

For the 321, the latest version of the Omega that includes the old 321 requires that the Delta at full wind is 20 seconds or less measured over 3 positions, and that the Delta at 24 hours after full wind is less than 30 seconds measured over 3 positions. The average daily rate must fall between 0 and +16 seconds per day.


For me it's not so much the actual numbers, although they are not within tolerance. It's that the numbers are worse after servicing - that's not something that normally happens. Unless the numbers are exceptional before the service (which is rare, and not the case here) you would expect them to be better.