Speedmaster WR Differences

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Hey all - could someone tell me why the Speedmaster Moonphase (304.30.44.52.01.001) is rated for one hundred meters of water resistance while the Speedmaster Racing (329.30.44.51.04.001) is only rated to fifty meters?

Both seem to have the same case, pushers, and non screw down crown. Is there something I'm missing?
 
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The racing is 14.9 mm thick, while the moonphase is 16.9 mm.

It’s probably the factor, my 2 cents.
 
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You need more WR on the lunar surface, than at the race track.
 
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The racing is 14.9 mm thick, while the moonphase is 16.9 mm.

It’s probably the factor, my 2 cents.
Oh didn't see that. I would have thought the crown gasket being the weak spot that would apply to both models.
 
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Oh didn't see that. I would have thought the crown gasket being the weak spot that would apply to both models.
It’s very likely that the gaskets are the same for both of them.

Our man @Archer may confirm this.
 
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So if that is the case then what would be the cause for the different rating?
 
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So if that is the case then what would be the cause for the different rating?
AFAICT, thicker case will have better WR.
 
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Hey all - could someone tell me why the Speedmaster Moonphase (304.30.44.52.01.001) is rated for one hundred meters of water resistance while the Speedmaster Racing (329.30.44.51.04.001) is only rated to fifty meters?

Both seem to have the same case, pushers, and non screw down crown. Is there something I'm missing?
304.30.44.52.01.001 Moonphase...

Case - 055CCZ005172 - rated to 10 bar
Crown - 069ST42262
Pushers - 086ST0202

329.30.44.51.04.001 Racing...

Case - 055CCZ007827 - rated to 5 bar
Crown - 069ST42262
Pushers - 086ST0202

Odd - not sure why they have different ratings.
 
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Regarding case thickness I didn't think that would make much difference at a benign depth of 50 or 100m. I.e. my Rolex Deep Sea it matters because you're at crush depth at 12k feet.

Maybe the extra 70psi is that stressful? Idk i'm not an engineer.
 
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Odd - not sure why they have different ratings.

Thanks @Archer for chiming in.

So does it mean what I often read in internet that case thickness will affect water resistance is a myth?
 
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Thanks @Archer for chiming in.

So does it mean what I often read in internet that case thickness will affect water resistance is a myth?
It can certainly be a factor, but without knowing all the design details it’s pretty hard to know for certain.
 
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Well the thinnest speedmaster that I know of (50th ann w/cal 3201 at 12.9mm thickness) has 100m rating. I think its a combination of caliber size/design and thickness that determines the WR.

Also for some reason the Trilogy speedmaster is 60m not 50m.
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