Technical Question About VPH

Reading Alex's post on VC's new 1907 got me thinking: the Zenith El Primero movement beats at 36,000, this new VC 1907 at 28,800, and my QP at 18,000... So what's the deal with VPH?

As I understand it, it relates to how smoothly the seconds hand will appear to be moving... but is more always better, or is there a "magic " number (28’800 VPH?), does the optimum VPH depends on the type of watch (sport vs. dress) or complication, and does the VPH can have an impact on the accuracy of the time keeping?
Has Zenith acheived a spectacular feat acheiving 36,000, and it is very hard for other movement manufacturers to replicate? 


basically has something to do with precision, the higher the
03/10/2009 - 23:44
beat the more accurate the watch and easier to regulate. The problem with high beat is that wear and tear comes faster and power reserve is normally lower. On the other hand with a high beat you can use a smaller balance to outweigh the power reserve issue... I personally prefer a more traditional 18,000 VPH with a nice big balance.
Some additional points...
03/10/2009 - 23:55
I believe the principle is that that higher vibrations tend to smooth out any inconsistencies in the movement's power delivery.  Power delivery can also be greatly affected by movement finish and manufactures like Vacheron achieve accuracy with time-consuming and expensive hand-finishing to their low-beat movements.  And like Alex said, the wear-and-tear factor is greatly reduced, and thus service intervals and expense, with low-beat movements. One other issue very important to chronographs with 36,000 vph like the El Primero is their ability to mark time down to 1/10 of a second.  When Rolex tuned down the Zenith movement to 28,800 for the Daytona, the result was that it could only measure intervals to 1/8th of a second.
Re: Technical Question About VPH
03/11/2009 - 02:49
Alex is right. It has to do with precision. With the 36,000 vibrations the El Primero could break seconds down into tenths accurately. The problem was the effect of the vibration speed on the movement. Apparently the engineers at Zenith solved the problem by integrating the bridge with the mainplate thus providing the stabilitiy required for this high a speed without the balance wheel supports disintegrating. I'm not sure, but this movement may be the only one to swing the balance wheel at that speed. The centrifugal forces and the strain on the parts must be considerable, thus the excessive wear. But at least the whole thing doesn't fly apart on your wrist! Joseph
A very good question and excellent simple answers. interesting to.....
03/11/2009 - 06:17

note also that many companies boast long power reserve and accuracy by using the small wheel balance and numerous barrels, which i unfortunately bought into.   so will i be able to see a beautifully crafted manual winding movement with large wheel balance, beating slowly but delivering accuracy and a long power reserve? of course it has to come with a sapphire back.  the kari voutilanen observatoire seemed to fit the bill which i regretably missed when i was offered, are there any others?  

thanks guys for the clear and simple answers!
03/11/2009 - 15:08

It is much appreciated

If any are ever delivered...
03/11/2009 - 23:59
...the Vyskocil VA has a large, slow beat balance. Best, GaryG
thanks. indeed a very good contender and i consider it a work of .....
03/12/2009 - 07:49
passion and dedication .  definitely a WIS watch. i really like the case design and the idea of a one-man made watch.
are you waiting for one too? (nt)
03/12/2009 - 10:11
More points on a great topic...
03/11/2009 - 16:42
Thanks for starting this's great to discuss some of the old myths .  High-beat movements are not always in practice more accurate.  While it was the theory that the higher frequency would compensate for power train inconsistencies, the same results could be obtained with better design, construction and finish to lower beat movements.  There was a period in the 60's when many manufactures jumped on the high frequency band wagon (Longines and Girard Perregaux come to mind) however some could not meet chronometre standards! Reading my earlier post again, I feel I wasn't clear regarding the advantage of high-beat chronograph movements.  They too are not always more accurate timekeepers, just more accurate stop watches.  They allow you to break down one second intervals into more increments and thus are capable of marking time to a smaller fraction, ie, 1/10 of a second for 36,600 vs 1/8 for 28,800. I'm not sure my reaction time on the pushers would be good enough to take advantage of the difference .  Nevertheless, I have fond memories of a beautiful Ebel El Primero...
Re: More points on a great topic...
03/11/2009 - 19:53
Don't forget the Concord, Dean. A very nice Chrono with the El Primero movement...very similar to the Zenith Chronomaster. Joseph
More precise, but not necessarily more accurate (nt)
03/12/2009 - 00:00
thanks for this clarification :-) (nt)
03/13/2009 - 00:34
Re: Technical Question About VPH
03/12/2009 - 01:45
thanks for the great info. this is new information for me. regards, matt
info from VC's technical department
03/13/2009 - 12:33
Historically movements had 2.5Hz (18,000 VPH) however progressively the frequency was raised to 3Hz (21,600 VPH) and now the norm is  4Hz (28,800 VPH). The higher the frequency the less the movement is subject to disturbances (shocks, friction...), regulation is also easier and you have greater accuracy over time. However higher VPH (ie 5Hz) need more energy, there is greater wear and tear on the components and the oils are less stables and can end up splattering on the components whereas the accuracy is not really any better. 
that settles it. Thanks again for all the info, I really appreciate it
03/13/2009 - 21:04