At least the broadband connection at home works, so I can write a little blog entry about this watch. Tintin from Thailand sent it in, and it’s probably the best UltraChron I’ve seen in this workshop. It’s in almost mint condition…
I love the 431 movement. Fast beating at 36,000 b.p.h, and built with the usual Longines quality. Great design, and I would wear this watch very happily indeed.
The condition of the case back is remarkable. The watch looks totally new old stock.
The dial is impeccable. Not the slightest mark, and as good as new.Still a remarkable performance considering the movement is totally dry, and that it’s so fast beating! But the amplitude is low, so a service is well in order.
The 431 is not only technically well made, it also looks very nice indeed.
The rotor is screwed to the automatic device bridge with a screw and two washers, which I find a bit unnecessary. In the end, you just want the inner ring of the rotor bearing to be tightly screwed to the bridge, and all other manufacturers achieve that with a single screw. Only Longines needs a screw and two washers 😉
The base movement. The shock system is a KIF, with its tell-tale shock spring design.
The 431 has a super date change, which is as snappy as a Zenith on a good day. A slow power build-up guarantees that there is minimal impact on beat rate and amplitude during the date change.
Oopsy. As the power reserve is a bit low, I am fitting a new mainspring. The original isn’t available any more (no complete barrel, no mainspring), but I find a very close 0.95 x .15 x 340 x 11.2.
Everything goes into the cleaning machine.
The new mainspring for the barrel.
Look at the condition of all the screw heads and the plate. Not a single scratch, no marks, nothing!
Just put together, this is looking very good, and we have a decent amplitude.
The automatic device is back together. Marvel at the condition.
Utterly pristine.Not a mark on the case either, and I really really would love to own this watch. Lucky Tintin!
What are compatible main springs?
Hi Christian, I’m working on Longines 431 and I need a new clutchweel for automatic. Can You help me or maybe suggest a adress for me…. I have only the very thin washer between rotor and the shrew. Can you help me?
Yours sincerely
Watchmaker Heidi Pettersen
NORWAY
Hi Heidi,
I’m afraid I don’t have the part you require. Everything I have is listed at https://watchparts.org.uk/
Kind regards,
Christian
Hello Christian,
I’m Claude.
Very interesting work ! I am amazed, nice.
I am the owner of an ultra-chron too. I have two questions.
1- When I put it off the whrist, it still working for an hour or two. Do I have to change the mainspring ? Subsidiary question, where can I find it ?
2-On the dial, there is the mention “automatique” for your type of ultra-chron and “Automatique” for mine. Is it an indication of the period of production ? Do you know that ? May be earlier for your’s.
Glad to visit your site.
Best regards
Hi Claude,
1. Your watch will most likely need a service.
2. I am afraid I don’t know.
Best regards,
Christian
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Hi Christian,
Thank you for the quick answer ! I am looking now for a clock service in my région (Chambéry-Grenoble).Do you have an advice ? I know it would be better with you, but your workshop is far away.
Best regards
Claude
Hi Christian, about how much service fee for the 431? Thks thks
Check out the price list on our website.
Best regards,
Christian
Hi Christian – I particularly enjoyed this post as you serviced my almost identical watch a few weeks ago (now keeping perfect time, thanks!). My watch is not in such good general condition, but the mainspring didn’t appear to need changing – any idea why this might be? Does NOT being used, as presumably this watch hasn’t been much, cause the mainspring to deteriorate?
The decision to change the mainspring goes as follows: if there is an original available, it’s a no-brainer, and I will always change it. If I can only get a mainspring that isn’t exactly the original size, I will leave the original mainspring. If the original is bent or “tired”, I will change it for the closest match available.
Lovely, absolutely green with envy.
Very beautiful. Does it come with a Flux Capacitor?
Simply majestic. It is as if time stood still.
Very nice indeed!
My only problem with owning such a NOS condition watch would be that I would never wear it in fear of inflicting any damage to it….
🙂
Only thing to do is….buy two so that you can wear one of the less tidy examples.
Very nice indeed Tintin.
I do like Longines.
Hi Christian. Thanks for servicing my watch and writing a blog post.
Best regards,
Tintin