Let's Tear The Back Off A Speedy !!!

[Tools]

Tired of looking at the insides of Rolexes...

Let's take a look at what makes the Speedy tick..

First, of course, we need some tools:....And, of course, a Speedy...


And, something for the Case-back. I like L-G tools...Made in the USA.
This L-G CWR-600, Waterproof Case Wrench should do the job..
The Speedy back has 6 slots, so I have it set to just use the two opposing positions with the notch sockets. If it had an odd number of slots or holes I would use all three sockets:


First step is to remove the bracelet to make it easier to work with:


The watch head needs to be secure to avoid slipping etc., so we clamp it up:


Carefully using the LG Case Tool, we crack it a bit, ensure no crud is under the case lip, clean things a bit, then voila, we pop off the cover:
The Speedy also has an inner cover that sits over the movement:


Inside we find one of my favorite movements, the Lemania 1861... Very close to the early 60's 321 MoonWatch movements but with more modern upgrades...Have to keep up with technology don't-ya'-know.


Omega uses a balance cock rather than the more robust full balance bridge favored by Rolex. This means a slightly smaller balance wheel, and the adjustment is made by adjusting the end of the hairspring.


Once done, we hand fit the inner cover and hand screw the case on, then tighten it up with the Case Tool.

Love that Sea Monster:

[DSJ]

Outstanding.

[toph]

WOW great pics and explanation

[Mike B]

Nice work ! It's nice to see a step by step tutorial on how to see the back of a Speedy

[Numismatist]

That is such a stunning movement, a shame it's not a clear back. Thanks for the viewing.

[Ken Cox]

Thank you, thank you, thank you!

I love this forum.

Now, if I understand this correctly (and I probably don't), Omega uses the 1861 movement in the solid-back Speedmaster; and uses the 1863 movement in the transparent-back Speedmaster.

Further, I understand these two movements have only cosmetic differences between them.

That said, the 1861 movement, which Tools has so wonderfully shown us in context, looks beautiful to me.

What cosmetic differences has Omega made between the two movements, assuming cosmetic and not mechanical differences?

[Paulie]

Where's the column wheel?!?!?

[Tools]

Originally Posted by Ken Cox

Thank you, thank you, thank you!

I love this forum.

Now, if I understand this correctly (and I probably don't), Omega uses the 1861 movement in the solid-back Speedmaster; and uses the 1863 movement in the transparent-back Speedmaster....
..What cosmetic differences has Omega made between the two movements, assuming cosmetic and not mechanical differences?

The major difference is the 1863 has replaced the Delrin (synthetic stone) brake for the stopwatch gears with a metal one. The Delrin Brake can be seen in this photo of the 1861 as the white lever just to the right of the center wheel.


And, here is a picture of the 1863 through the caseback:

[Perdu]

Originally Posted by DSJ

Outstanding.

x2

[kelly56]

Love it.

[JJ Irani]

Great work as always, Larry. Nice pictorial!!

[Andad]

Great pictorial Larry.

The delrin brake (a Dupont acetal resin) is used in the non sapphire back Omegas as Omega didn't want anyone to see a 'plastic' part in their movement.
I'm sure that there is a proper Omega 'castle' tool for removing the back from Omega watches. Most who use the tool shown will slip and badly mark the watch case and/or back so - be warned.
Larry, with his experience, makes it look easy.

[Lol-x]

Awesome Larry

The quality of those photos is only complimented by the beauty of the movement

[airhkg]

Very nice pics. Let's have some thoughts on the full balance bridge. Now the Speedy with it's balance cock was and is approved by NASA for space flight. If I recall the Rolex Daytona failed.. badly. I am curious of the Daytona's of that vintage had the full balance bridge or no?

[valenciajewelers]

Cool. I love those watches. And we use that case wrench here on a daily basis. Don't think a day goes by without someone needing a battery. One lady brought in 3. lol.

[Tools]

Originally Posted by airhkg

Very nice pics. Let's have some thoughts on the full balance bridge. Now the Speedy with it's balance cock was and is approved by NASA for space flight. If I recall the Rolex Daytona failed.. badly. I am curious of the Daytona's of that vintage had the full balance bridge or no?

When the trials were conducted back in the 60's, there really wasn't a "Daytona" contender.

The NASA requirements back in the 60's were for a manual wind chronograph, all watches of the time had acrylic crystals.. The Rolex Chronograph used the Valjoux movement then, which is now owned by ETA, and yes, it did have a balance cock.. And the movement didn't fail "badly", the hands warped during the temperature testing, blocking it's ability to turn..

Out of the three finalists, from this competition 45 years ago: Omega cal 321, Rolex Valjoux 72, and Longines Cal. 13ZN, here's how it went down.

Results of the tests :

Omega Speedmaster : gained 21 minutes during decompression test and lost 15 minutes during the acceleration test , the luminescence of the dial was lost during the test

Rolex Cosmograph : stopped running on two occasions; during the relative humidity test, and during the high pressure test when the sweep second hand warped and pressed against the other hands

Longine Wittnauer : Crystal warped and disengaged during the high pressure test , same fault occured during the decompression test

Final conclusion : the Omega chronograph performed satisfactorily

No Daytonas have been tested by NASA with either the Zenith movement or the in-house 4130.

[airhkg]

Very interesting. Yeah.. an automatic wouldn't really work in zero / micro gravity!