Regarding Accuracy

[ROlesorusLEX]

My wife enjoys a 1990 YG DD. She's the second owner, as she loves vintage watches. It gains about 16 s per day. She and I are not really bothered by that, but we were discussing why/whether older watches run fast. My dad has a 1987 DJ that also runs quite fast. He said it was slightly slow when he bought it new.

A couple of questions:

1. It seems like older watches run faster as they age. Is this actually correct, or do we just have 2 examples that happen to do so?

2. If true, why is this? I understand the lube dries up or becomes less viscous, gears wear, etc. But do the gears actually lose some diameter, or is there some other cause?

Just curious about the actual mechanical processes involved. Perhaps educated forum members or watchmakers can weigh in. Thank you for satisfying our curiosity.

[TswaneNguni]

My oldest watches ,2007 16613 and 2011 DSSD running slightly faster +3/+4 .Crown up overnight less 1s.
A watch thats starts running slow needs service ,thats what the one AD says (Decades of experience )

[MikeyV]

I'm sure others will chime in with technical details, bu there's no reason that watch can't run nearly spot on after a service.

Do you know of it's service history by chance? The oils do definitely degrade over time.

[Tools]

Originally Posted by ROlesorusLEX

. . .

2. If true, why is this? I understand the lube dries up or becomes less viscous, gears wear, etc. But do the gears actually lose some diameter, or is there some other cause?

Just curious about the actual mechanical processes involved. Perhaps educated forum members or watchmakers can weigh in. Thank you for satisfying our curiosity.

A watch ticks based on the mainsprings torque at the pallet fork, which, in turn, imparts an impulse/motion to the hairspring/balance wheel.

If the pallet fork, for any reason such as lack of lubrication, is not able to push the balance far enough for a full oscillation, the balance makes a shorter/quicker oscillation (lower amplitude). This shorter oscillation takes less time, and less time means a faster ticking watch.

[214270Explorer]

Your watch is simply in need of service after all those years. My OPD did that too after 28 years and a $550 Rolex service made it run new again.

In fact, when new it was +4.3 sec/day and now after its service in 2016 it is +2 sec/day. It was also running faster before service and the tech told me that it was due to a weakened(?) main spring.

Whatever. Have it serviced.

[Robf52]

Originally Posted by Tools

A watch ticks based on the mainsprings torque at the pallet fork, which, in turn, imparts an impulse/motion to the hairspring/balance wheel.

If the pallet fork, for any reason such as lack of lubrication, is not able to push the balance far enough for a full oscillation, the balance makes a shorter/quicker oscillation (lower amplitude). This shorter oscillation takes less time, and less time means a faster ticking watch.

Thanks for the explanation.

[ROlesorusLEX]

Originally Posted by Tools

A watch ticks based on the mainsprings torque at the pallet fork, which, in turn, imparts an impulse/motion to the hairspring/balance wheel.

If the pallet fork, for any reason such as lack of lubrication, is not able to push the balance far enough for a full oscillation, the balance makes a shorter/quicker oscillation (lower amplitude). This shorter oscillation takes less time, and less time means a faster ticking watch.

Yeah, great info. That's what I was looking for. That's why this forum is so cool. Thank you very much.

[Rado63]

The movement is 3055 chronometer certified. Needs the full service, tell the service team, how much restoration or service you want to the watch and get it fixed up.