Note on the New asian 7750 movement/a07.211

[gran]

The new asian 7750 movements around do not have 25 jewels in them!!!

(Jewel = jewel-lined pivot hole with ruby red colour)

The New 37mm Asian7750/a07.211 is larger in diametre than the asian7750 and ETA 7750 movement,

and is same larger size as the new ETA Valgranges.

These larger 37mm New Asian 7750 (=a07.211) movements fit well in larger watches,

like the CHOPARD GTXXL Chronograph

However the new 7750 around appear to have very very few jewels in them,

but have more than 15 metal bearings instead (This has also been confirmed by The Zigmeister)

Jewels = A jewel bearing is a bearing in which a metal spindle turns in a jewel-lined pivot hole with ruby red colour. Jewel bearings were invented in 1704 for use in watches by Nicolas Fatio de Duillier, Peter Debaufre, and Jacob Debaufre, who received an English patent for the idea. Originally natural jewels were used, such as sapphire, ruby, and garnet. In 1902, a process to make synthetic sapphire and ruby (crystalline aluminum oxide, also known as corundum) was invented by Auguste Verneuil, making jewelled bearings much less expensive. Today most jewelled bearings are synthetic ruby or sapphire http://en.wikipedia.org/wiki/Jewel_bearing

So is the new asian 7750 (= a07.211) a bad movement? The Zigmeister said that, and I quote;

"When you design and build a movement with metal jewels not sapphire ones, then expect to see metal jewels. This is how this particular A7750 has been build and designed. If there were no jewels, then you could blame QC, but not in this instance, QC is working just fine, all the jewels are in place and doing what they are designed to do..Many vintage pocket watch "jewels" are nothing more than holes in the brass plates, clocks are the same, the pivots turn in the brass plates."

However the dealers do not properly describe this new asian 7750,

and certainly do not advertise that metal bearings have been used

A pictorial description of the asian a07.211 (= New A7750) movement below:

First a comparison of the new 7750 (= a07.211) and SWISS 7750 and normal asian A7750

A partial breakdown of the new Asian A7750 (= Asian a07.211)

As a finishing note, I hope and pray The Zigmeister or any other of our excellent watchmakers do a more detailed review on this topic so all (RWG menbers and Dealers alike) can be well educated about this and other asian 7750s around so members do not end up getting a big surprise

+ I will post more on this topic later

Thank you

Gran

[Rolexman]

Thanks for bringing this to our attention!

[gran]

Youre welcome Rolexman

[Toadtorrent]

Whoaah...that's interesting. What has Domi or Zig said about the durability of the approach of using bearings instead of jewels? I don't imagine this is a good thing.

[gran]

Whoaah...that's interesting. What has Domi or Zig said about the durability of the approach of using bearings instead of jewels? I don't imagine this is a good thing.

I agree that it is probably not a good thing and certainly I do not like it

Maybe it is cheaper to make? If so we are getting screwed on price

It is certainly not the most honest thing of the dealers not to describe this movement properly....they should give RWG the information we need to make informed purchases

The experts have said very little about this larger diameter movement so far but:

Francisco apparently knew about these metal bearings as well but has said nothing about the quality of this movement so far....Domi gave no indicatons that it is a quality movement and changed the movement for me recently...while The Zigmeister being an horological expert also on ancient clockwork, clearly states that the metal is no problem as long as these movemenst are serviced regularly...but truth is the details about the quality and durability of this movement is still very much in question

All the best

Gunnar

[Toadtorrent]

Thanks for the feedback on this. Very interesting indeed.

[Francisco]

in some parts it is not so important not having a jewel. For example, in the minute counter. it is really the same to have a jewel or not there. because normally the chrono is off, and if it is on, only rotates a bit per minute.

the problem could arise in the parts that are always rotating. if there is no oil there, jewel is more resistant to wear.

regards,

Francisco

[RWG Technical]

I think it's important to consider the original Valjoux 7750 as well as the new ETA versions of this movement.

Valjoux 7750's (and many other vintage movements) originally had only 17 jewels, which is the minimum for a plain handwind movement, add a chronograph, and an autowinder and you have many pivots with no ruby jewels for them to turn in.

There are many metal jewels in the original Valjoux (and ETA 17J) 7750's, these movements have been running just fine for over 30 years and if serviced regularly have no wear problems.

The latest version of the ETA 7750 with 25 jewels still has some metal jewels, and the ETA 7753 (which is only a few years old) has many metal jewels, and works just fine.

So metal jewels in themselves are not a problem, in fact a metal jewel is much better than a "red" coloured one that may not be anything more than coloured glass or a soft material.

The key to long life hasn't changed, have it serviced regularly, before it wears out...

[gran]

I do accept that you are the true expert on this The Zigmeister and I am just doing my best to examine this from my own experiences

I accept that servicing the movement is the key to long life

I accept that metal bearings have their role and may work well

What is worries me is the lack of decription of the movements

I do not expect or want a movement lacking the jewels, especially not in the positions pointed out...

According to your comments it was silly of me to try to change the movement in this case (in germany) as the movement was fine as it was and only needed service

That aside.....you are now saying that coloured glass or a soft material is being used as well just to make things more convoluted.

Certainly we do not want coloured glass or a soft material..it would certainly be even worse if that was used obviously what we want are true quality jewelled bearings (jewelled bearings = synthetic ruby or sapphire)

[RWG Technical]

We have both been around these forums for long enough to know that not everything is as advertized, I see so many variations in everything that it's not worth trying to keep up with the changes.

On the coloured "glass" I believe that all of our A7750's have sapphire jewels, my teardown of the 4 year old A7750 proved this, I haven't seen anything to tell me otherwise.

My point was that there are some movements with "coloured" glass for jewels, these will wear out the pivots very fast. So just because you see a "red" jewel, it may be worse than having a metal jewel.

[gran]

We have both been around these forums for long enough to know that not everything is as advertized, I see so many variations in everything that it's not worth trying to keep up with the changes.

On the coloured "glass" I believe that all of our A7750's have sapphire jewels, my teardown of the 4 year old A7750 proved this, I haven't seen anything to tell me otherwise.

My point was that there are some movements with "coloured" glass for jewels, these will wear out the pivots very fast. So just because you see a "red" jewel, it may be worse than having a metal jewel.

Yes you are correct!

Good that you have not seen this "glass" in 7750s

I would have been even more delighted if you (and other movement experts) would post even more on these issues for RWG. As when a new potentially important movement such as this new A7750 "Chinese a07.211" is introduced..we and the dealers need input and detailed knowledge... but I perfectly understand that this steals precious time from you (and others). You guys see it all regarding the movements!!! while the rest of us have a much more limited set of items, resources and experiences to draw upon.

and Yes! It would indeed be worse

Escape, second and possibly also third, and great wheels placed in the gear train toward the mainspring barrel do have metal bearings and not jewelled bearings....I can not beleive this is a good thing in these postions

Regards

Gunnar

NB! I am also adding an image from a dealersite where the jewelled bearings in two of the most easily spotted positions, such as chronolever and escape, appear to be present at these positions...so maybe not all of these new 37mm movements are identical in how they are put together?...if so it is good