Asian 7750 slow beat movement,info needed please,is there such a movement?

[Tommyv5]

I just took delivery of used Hublot King Power 48mm Oceanographic 4000 Titanium V2 from the V6 factory,can anyone identify the movement? Here is my issue as follows ,I own four of these and they all have 7750 movements with a super smooth second hand sweep. This particular one seems to NOT have a smooth sweep,the second hand moves like a 21,600 BPH movement. I opened one of my other 4000's and it seems to have the same movement. I have compared the sweep side by side and this one is not as smooth but it still keeps accurate time. The movement in question was serviced by speedy.Do they make a 7750 with a slow beat sweep? I own a lot of watches and can immediately tell the difference between 21,600 BPH and 28,800 BPH.I added pics of the watch and movement,is there any explanation for this,any help is appreciated,thank you.<br><br><i>Hublot King Power 48mm Oceanographic 4000 Titanium V2 from the V6 factory<br><br> <br><br> <br><br> <br><br> </i></i>

 

[ado213]

This looks weird, Got to say I haven't come across this movement before, but there are low and high beat 7750's if this helps you. By the way if this ever breaks down let me know, would love to strip it !

 

[Jaguarman]

Yes, there is a “low beat†version of the 7750 in both the Chinese version as well as the older gen ETA versions, however the term “high beat†has always been a relative term.

I’m no expert but I believe that there were many (high end) watches prior to the 1960’s, with accurate chronometer grade movement, which only ran in the 10-11,000 bph range.

I still have a Bulova automatic that I purchased new in 1965, which I believe runs in this range. Curiously the large second hand sweeps smoothly and the watch has always been quite accurate, even though it was only serviced once about 30 years ago.
I believe that one of the first “high beat†movements was produced in the 1960s by Seiko. It ran at 18,800bph. A few years later they produce one that ran at 36,000bph. So, it would seem that while the newer 7750 runs at 28,800, the older version at 21,600bph (while it is slower) in the long term scheme of things should not be referred to as a “low beat†movement.

The mystery to me is that when a true “low beat†(11,000bph) movement can reach chronometer grade accuracy why is the high beat version so important?

The second hand on my new Navitimer01 (21,600bph) is clearly not as smooth as the one on my fighters, which has an ETA7750 28,800 bph movement. What I can’t seem to figure out is why the second hand on my old Bulova, which runs at less than half that speed, appears just as smooth at the 28,800bph version. Could there be something else at play here. Also, it would seem to me that the higher the beat, the faster some parts would wear out.

I would love to hear others opinions on this.

 

[Mirage]

On the image below, the "missing screw is in fact an adjustment cam for the chrono clutch. This cam sets with how much load does the chrono driving gear is pressing against the chrono seconds gear. If too much load is applied, you will feel that the gear teeths are locking themselves too hard and this will create a erratic sweep.

see how it all works at: http://www.eta.ch/swisslab/7750/7750.html under start/stop /reset