Power reserve test

[Rory]

I’ve got a Tudor Blackbay Chrono which doesn’t perform to specs regarding the power reserve. It’s been back for repair under warranty once already around 6 months ago but I’m only getting around 40 hours max rather than 70. I’ve fully wound the watch, worn from 7am to 10pm each day for a week and then left it on the side. Is there anything else I should do before sending this back for repair again?

Cheers
Rory

[ben4watches]

What you should be doing is fully winding the watch and leave it alone after noting the time and then monitoring when it stops.

By winding it then wearing it you may not be active enough to keep the mainspring fully wound and when you are resting it up it may not be fully wound.

[Rory]

I’ll give that a try - thanks Ben.

[walkerwek1958]

What you should be doing is fully winding the watch and leave it alone after noting the time and then monitoring when it stops.

By winding it then wearing it you may not be active enough to keep the mainspring fully wound and when you are resting it up it may not be fully wound.

Couldn't put it better, I find it surprising that owners can’t work that out for themselves.

Fully hand- wind the watch and see how many hours it runs for, that’ll show whether the mainspring or barrel are faulty. Next step is to fully wind the watch.........and I mean fully wind........then wear it and see how it performs when worn regularly. Store the watch dial up overnight unless you’ve a good reason not to and note the time morning and night versus a reliable source.

How many winds of the crown does it take to fully wind the watch?.....I don’t know, but I know I don’t know, so I’ll give it 100 twists which is certain to be enough.

Gather some data and think about what it’s telling you, it isn’t rocket science. As a general rule the auto- winding either works properly or it doesn’t work at all, likewise with the mainspring and barrel, on a newish watch it’s either right or it isn’t.

Inactive wearers is a problem with automatic watches, I’ve had a few sent to me with absolutely nothing wrong but the owner claims the watch has a poor power reserve.

[Boss13]

I remember when I bought my first proper watch, which was a Submariner. I wore it out of the shop, wore it everyday and only took it off overnight.
I never once wound that watch in probably 8-9 months and it didn't stop. There was probably only the odd 1 or 2 days in that time when I didn't wear it at a weekend. Looking back, it was quite nice!

Sadly the bug has bitten since those days and now having more than one watch means the above never usually happens. I do sometimes find the watches need charge more often than I think they should so may also do a test.