That is total rubbish performance, so yes it needs regulating.
On the wrist my 3 month old IWC 8 day gains about 6secs a day but when at rest anyway up,down etc it gains at least twice as much. Why is this happening and does it need regulating? Ta.
That is total rubbish performance, so yes it needs regulating.
I don’t like movements designed to run for 8 days, there’s more likelihood of the watch running in a low state of wind and that won’t help the timekeeping.
First check is to confirm the watch is running in a high state of wind. I suggest hand- winding fully, then wear it and check the rate again. Wear it a full day (around 16 hrs), checking against a known accurate source, and calculate a rate per 24 hrs. Leave the watch dial up overnight and do the same. Wear the watch normally and repeat the process.
It’s quite likely that the watch is running slightly fast and needs regulating, but its worth checking as I suggest to confirm what exactly it is doing. What I find strange is the claim that it gains the same amount off the wrist regardless of position to give a value that is much higher than the ‘on the wrist’ rate, that doesn’t make sense to me. Get a set if numbers and be sure to calculate the rate correctly when making comparisons.
One of the resident watch makers will be along in a minute:
Edit: beat me to it!
There is always a bit of variance dependant on which way the watch is orientated,
With regard the performance, it does not sound great but dependant on the movement used and the specs of that movement it could be in the designed tolerance. State of wind may also have an effect.
I would take it back to the AD and ask for clarification but they could say it’s within spec.
Just out of curiosity, when you say 6 seconds a day, are you checking every 24 hours or after six days and dividing by six? Because if you are leaving it sitting for six days, with an 8 day barrel, then there are few watches that behave well at the latter end of their power reserve.
If you want a clearer idea of performance check every 24 hours and wind fully every day.
Definitely worth winding every day whilst checking, that eliminates any effects from the watch running in a lower state of wind.
Thanks folks, I’ll do more objective calculations. That’s why I prefer cosc regulated watches - you’ve got them by the goolies if it doesn’t keep within the stated tolerances. Or I’m spoiled by my Spring Drives…
I don't think that's bad. It's slightly better than my Mk XII and about the same as my Speedy. On the other hand it's not nearly as good as my handwound Merkur, which cost me £70 or something. I'm afraid it's a bit of a lottery.
On wrist it's experiencing a range of positions that it's been adjusted in.
Off wrist its just running in one position which will affect timekeeping - its why old rolex guides used to say to gain place this way, to lose place other way, etc.
8 day movements tend to have a variation in daily rate some starting fast at full wind and running slower with power loss etc.
It doesn't sound like your watch is misbehaving or has an issue, and it isnt cosc certified so can have a tolerance outside of 0-4+6, even up to +12 but if youre not happy with the running speed you should be able to get it regulated, perhaps not within warranty but worth a go.
When wearing though +6 is considered acceptable even for a cosc watch.
Personally as a not really bothered about accuracy type, id set it at a minute slow and after a month it would be 2 mins fast if I wore it all the time. Not that bad no?
NB Am not an expert.
Definitely need to gather more carefully measured data to assess what's really going on. A non COSC watch in good condition should still be capable of running between -2 and +6 with careful regulation but precision will be poorer, it'll show more variation dependant on wear pattern etc.
Get some good numbers over a couple of weeks, winding every day.
Originally Posted by Slamdoor;[URL="tel:6113747"
COSC only applies to uncased watch movements and at the time of manufacturer. A lot of non COSC brands and even COSC now state better than COSC - depending on the moment for their watches. It really depends on age and movement regulation.
Last edited by MartynJC (UK); 30th November 2022 at 14:43.
“ Ford... you're turning into a penguin. Stop it.” HHGTTG
Find me any lever escapement watch that keeps time well when it's in the latter half of its reserve. That's more about the way that a spring can deliver torque and the effects of reduced torque than about any movement.
Some of my watches gain or lose 30 seconds a day, some probably wouldn't in a decade. Horses for courses.
In my limited experience, state of wind makes a massive difference to timekeeping. My IWC Mark18 is literally spot on (+/-0 per day) when worn throughout the day and dial up over night but if I don't wear it for periods throughout the day it drops well out of cosc.
Agree with Matt’s comment, it’s not rocket science.
As a mainspring unwinds the torque applied to the barrel is fairly constant over the first 50% but then starts to fall in a non- linear fashion. This translates to a drop in amplitude, as it falls the rate will change and the positional differences will increase therefore the watch will be more sensitive to wear pattern.