Chrono-second-hand jumps back when started

Martino · Dec 31, 2019

Hi guys, when I start the Chronograph of my 1861 (3570.50.00) the second hand jumps - sometimes - 1 to 2 seconds backwards before running forward normally. A problem or normal? Any thoughts?
Thx in advance.

Dan S · Dec 31, 2019

Problem.

Pvt-Public · Dec 31, 2019

Martino
Hi guys, when I start the Chronograph of my 1861 (3570.50.00) the second hand jumps - sometimes - 1 to 2 seconds backwards before running forward normally. A problem or normal? Any thoughts?
Thx in advance.

What are your thoughts? A device used for timing things that is off by 1-2 seconds from the start. Come on you answered your own question.

gpssti4 · Jan 1, 2020

Of course it is but I’d imagine a service would sort it out.

Professor · Jan 1, 2020

Be nice to hear some theories as to what may be causing this. Perhaps from someone who has run across a similar problem and fixed it or had it fixed.
I've noticed that some , mainly old worn mechanical but sometimes new quartz movement, watches can occasionally jump forwards or back a few seconds or even a minute or two when pushing in the crown after setting the time. Not always of course or the watch would be useless. A second try usually works out okay.
Perhaps a burr on the stem ?

ChrisN · Jan 1, 2020

This sounds like an issue with the hammer when it releases the chronograph runner that the seconds counter hand is fitted to.

Firstly, take it to a watchmaker and ask them to demagnetise the watch. If the hammer or runner "heart" is magnetised, then you can get a jump.

If that doesn't resolve the issue, then it probably needs a service as the oil on the hammer is dirty or old. Do you know when it was last serviced?

Good luck, Chris

Archer · Jan 1, 2020

Chris has given you the two most common reasons for this - magnetism or gummy/too much oil on the hammer. I have seen other causes for it that are more obscure, such as this one where the chronograph bridge was bent slightly. This allowed the chronograph wheel to be higher than it normally would be (pushed upwards by the friction spring) and when the hammer moved away from the cam when the chronograph was started, it was just slightly dragging across the chronograph wheel, causing the wheel to turn backwards before moving forwards...

So the easiest solution as Chris noted is to demagnetize the watch, and if that doesn't work a watchmaker will have to look into the issue further to understand the cause.

Cheers, Al

abgul · Feb 18, 2021

I have a Chrono where the second and minute hands are jumping backwards before starting. Would demagnetising still be first port of call?

JimInOz · Feb 18, 2021

A abgul
I have a Chrono where the second and minute hands are jumping backwards before starting. Would demagnetising still be first port of call?

Archer
.................................

So the easiest solution as Chris noted is to demagnetize the watch, and if that doesn't work a watchmaker will have to look into the issue further to understand the cause.

Cheers, Al

Chrono-second-hand jumps back when started

Martino

Dan S

Pvt-Public

gpssti4

Professor

ChrisN

Archer

abgul

JimInOz

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