My watchmaker believes these are great movements, but the set-bridges wear out. Do you here concur, and know why this happens if so? Cheers, M'Bob
It is a fairly complex, flat, thin spring that has quite a force applied to it whenever you pull the crown out - a pin has to move between two semi-circular cut-outs with a divider between them, using only the force you have.to apply to move from one cut-out to the other There is only so much elasticity that tempered steel can retain, so it is not uncommon for them to exceed this elastic limit and crack. Grease is applied here during a service to aid the movement so, if the service interval is not maintained, the forces can become greater than what was intended. Not sure what this one fits, but you can see what I mean. The problem is fairly common to all watches.
I would have called this part a setting-lever spring rather than a set-bridge but I am sure either term is OK. I don't think there is anything particularly unusual about the cal 5xx ones, is there Al? I know that the 'bumper' 3xx series ones are prone to breaking too. Hence I have a little stash of them in my spares box . . .
I've had 3 set bridges that needed to be replaced on this series of calibers. However, since that's out of 5 or 6 dozen that I've owned I wouldn't call it a pandemic.
The name depends on where you are located in the world, and how long ago you had any formal training. Set bridge, setting lever spring, setting lever jumper - all names I have seen for this part or similar parts on other watches. And no these are not terribly prone to breaking in my experience. I have certainly replaced them, but it's not really what I would call a common problem. Cheers, Al
It is a good source of buying, otherwise fine, watches on eBay. I have bought 4 or 5 that were described as broken and all they needed was a setting lever spring and a service - in fact, that's exactly how I got into watch tinkering.