I've got a reasonably large watch collection, most of which I never wear although I do wind them periodically.
One thing I have noticed lately is that a couple are running really fast, gaining something like 5 minutes per hour.
What is the reason for this?
I'm inclined to think they could be magnetised somehow, they haven't suffered any shocks, or perhaps they just need servicing?
TBH the couple in question, although very nice are not valuable and will only be sat in the collection so not worth the price of a service.
My question is theoretical mainly as apart from the hairspring I can't think why any watch would exhibit such a gain in speed.
Anyone any ideas?