Speedmaster '57 clasp on 321 bracelet

[fskywalker]

Originally Posted by tzwick

That sounds awesome! Having the push button quick adjust functionality on the 321 bracelet would be a great upgrade. Thanks for sharing your findings, and definitely let us know the part number once you get it. I'm sure others will find this info helpful!

You’re welcome! My findings apply to the 50th anniversary flat link bracelet (020STZ011626); not sure if the same would apply to the 321 bracelet.

[fskywalker]

Originally Posted by EEpro

Was able to find a 117STZ015404. Probably Friday arrival with holiday.

Based on my measurements on the 50th anniversary it is not compatible without modifications.

Hope the Speedy 57 clasp fit on the 321 bracelet without the need of other parts or modifications !




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[brandrea]

I’m not gonna lie, it would be nice to have some on the fly adjustability on the 321.

Again, I’m not sure it trumps losing that beautiful vintage logo on the clasp though …

[EEpro]

Originally Posted by fskywalker

Based on my measurements on the 50th anniversary it is not compatible without modifications.

Hope the Speedy 57 clasp fit on the 321 bracelet without the need of other parts or modifications !




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Here's the EW clasp situation.

Part hasn't hit the boutique yet so we are looking at Friday at the earliest. Probably Monday though.

[samson66]

Originally Posted by fskywalker

Got today the Speedmaster 57 clasp:



It is longer than the 50th anniversary clasp, extra length to accommodate the 2 position pushbutton:





The clasp arm assemblies are exactly the same length, but the shape of the 57 arm that close against the clasp is different as shown below (on top) to clear the push button :



The arm of the 57 clasp is about 1 MM wider, so it won’t fit into the 50th anniversary bracelet interconnecting link groove without modifications:



Also note the shape of the head of the pin that goes into the clasp when lock in the closed position is different (tip of the 50th is round, 57 is more flat):



Here you can see the difference in width of the 57 arm versus the groove on the 50th interconnecting link:




I installed the extending arm of the 50th clasp into the 57 clasp and it does fit, but then it is pretty hard to close the clasp as the shape of the arm collides with the inner push button so won’t work properly.

This means the 57 clasp would not work as a direct swap into the 50th bracelet by itself. If someone could source the interconnecting link from the 57 bracelet (shaded in yellow below) you could swap it with the 50th interconnecting link and should work without modifications:



But that part has been discontinued by Omega

The other option is to shave either the 50th anniversary interconnecting link or the Speedy 57 clasp arm approximately 1 MM so that they fit together. I will inquire with Omega if the interconnecting link for the 50th bracelet can be ordered. If available will probably order one and shave it to fit the 57 clasp arm; if not will probably shave the arm of the 57 clasp. Stay tuned!


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Excellent information and write-up. That's a bummer that it isn't a direct swap. Good luck in your efforts.

[fskywalker]

Originally Posted by EEpro

Here's the EW clasp situation.

Part hasn't hit the boutique yet so we are looking at Friday at the earliest. Probably Monday though.

The width of the clasp arm on the 50th anniversary is about 6 MM while on the Speedy 57 is about 7 MM. if the width of the arm in your 321 clasp is about 7 mm should be a direct swap.




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[EEpro]

Originally Posted by fskywalker

The width of the clasp arm on the 50th anniversary is about 6 MM while on the Speedy 57 is about 7 MM. if the width of the arm in your 321 clasp is about 7 mm should be a direct swap.




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I'll take a caliper to it when I'm back at home. With the leatherman here at the pool it looks like 6.5 mm.

Can you just file 0.5mm off each side of the little interface that sits inside the link and use the rest of the clasp as is?

[fskywalker]

Originally Posted by EEpro

I'll take a caliper to it when I'm back at home. With the leatherman here at the pool it looks like 6.5 mm.

Can you just file 0.5mm off each side of the little interface that sits inside the link and use the rest of the clasp as is?

Yes you could shave .5 MM on each side of the interconnecting link groove or at the arm.

Don’t want to modify the 57 clasp, but rather modify the interconnecting link as long as can get an extra ordered (imagine is about $70) to have it just in case decide later to sell the bracelet back on its original conditions.


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[EEpro]

Originally Posted by fskywalker

Yes you could shave .5 MM on each side of the interconnecting link groove or at the arm.

Don’t want to modify the 57 clasp, but rather modify the interconnecting link as long as can get an extra ordered (imagine is about $70) to have it just in case decide later to sell the bracelet back on its original conditions.


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Got it. Just want to see what would be needed if it doesn't work for me.

EW bar width is confirmed at 6.5 mm per mitutoyo.

[fskywalker]

Originally Posted by EEpro

Got it. Just want to see what would be needed if it doesn't work for me.

EW bar width is confirmed at 6.5 mm per mitutoyo.

My Mitutoyo is out of batteries

Reading on a scale think it is 7 MM width so you probably need to shave .5 MM to make it fit





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[EEpro]

Originally Posted by fskywalker

My Mitutoyo is out of batteries

Reading on a scale think it is 7 MM width so you probably need to shave .5 MM to make it fit





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Thanks for this pic.

It's definitely 0.5 mm bigger than the EW bar.

I think since it's only 250 micrometers from each side I'll tape some 3M 400 grit abrasive on the work bench and just swipe the top section 10 times on each side, measure, repeat until I hit 6.5 mm. It's so minor I don't think you'll be able to tell if the grain is all in one direction.

There's also some slack in that joint that will help a lot.

[fskywalker]

Originally Posted by EEpro

Thanks for this pic.

It's definitely 0.5 mm bigger than the EW bar.

I think since it's only 250 micrometers from each side I'll tape some 3M 400 grit abrasive on the work bench and just swipe the top section 10 times on each side, measure, repeat until I hit 6.5 mm. It's so minor I don't think you'll be able to tell if the grain is all in one direction.

Sounds like a plan ! Please update when you get it done!


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