No.27 Clasp repair

Bernardino · Jun 6, 2025

Hi

I have a Chronostop with the mesh bracelet and corresponding No.27 clasp. I find that the clasp is difficult to close securely and will open while I'm wearing it.

Are there any tips for preventing this? is it possible to repair or should I just start to hunt for a new one that may be in better condition?

appreciate that it's over 50 years old and seen lots of wear but just want to avoid the watch falling off my wrist

Wat-1 · Jun 7, 2025

Bernardino
Hi

I have a Chronostop with the mesh bracelet and corresponding No.27 clasp. I find that the clasp is difficult to close securely and will open while I'm wearing it.

Are there any tips for preventing this? is it possible to repair or should I just start to hunt for a new one that may be in better condition?

appreciate that it's over 50 years old and seen lots of wear but just want to avoid the watch falling off my wrist

Please send a few photos

Clelow · Jun 8, 2025

Perhaps a simple adjustment will remedy the problem.

Jan Dietrich · Jun 8, 2025

Often you just have to bend a Part of the clasp. But we need photos to see wich part. There are also many videos on YouTube on this topic

JimInOz · Jun 8, 2025

First thing is to check the curvature of the two blades of the clasp to ensure they aren't causing the clasp cover to spring open. They should mate or nest closely together and can be gently bent to get correct alignment.

Second thing is to check that they are not too curved (clasp coverall be short of the catch point) or too flat (clasp cover will be past the catch points. The catch points on the clasp are shown by the black arrows.

If all blades are correct, the locking is done by the clasp cover locking to the bottom blade at the catch points on the sides of the clasp/blade.

The sides of the clasp cover should snap down onto this part of the lower blade.

Seen from below.

If the "snap" when you close the clasp isn't firm, you can use flat nose pliers to gently bend the side of the clasp cover inwards at the catch point.
It won't take much so only do a very small adjustment at a time.

Bernardino · Jun 9, 2025

Thanks for advice, I’ve used some pliers on the clasp cover and this has tightened the end where the logo is and it closes and it snaps together nicely .

I’ve attached some pictures including of the clasp closed (apologies for the quality.) you can see that the end that folds on itself (non logo end) doesn’t snap into place. Is this correct or should both end snap into place?

JimInOz · Jun 11, 2025

Bernardino
should both end snap into place?

No, Only the logo end.

The other end may hang down slightly, depending on how well the curved blades are adjusted. The bracelet also stops the back end of the clasp blades from sitting flush.

If you remove the bracelet from the upper clasp, you can see that the upper clasp now closes neatly down on the lower part.

If the clasp closes relatively flat and the "snap" is firm, it should be OK.

Bernardino · Jun 11, 2025

JimInOz
No, Only the logo end.

The other end may hang down slightly, depending on how well the curved blades are adjusted. The bracelet also stops the back end of the clasp blades from sitting flush.

If you remove the bracelet from the upper clasp, you can see that the upper clasp now closes neatly down on the lower part.

If the clasp closes relatively flat and the "snap" is firm, it should be OK.

Thanks Jim, that's really helpful. after some adjustments my clasp is look more like the top picture in your reply and it feels more secure on the wrist

No.27 Clasp repair

Bernardino

Wat-1

Clelow

Jan Dietrich

JimInOz

Bernardino

JimInOz

Bernardino

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