Fast-beat Vs Slow-beat Movements.

[padi56]

The high-beat vs low-beat argument has been running as long as I've taken an interest in movements around now over 55 years (I am talking about watches here) and opinions are still divided. Sorry for the long read for those who have difficulty reading long posts

One of the more highly regarded chronograph movements is still the Zenith "El Primero" running at 36000 BPH. So highly regarded as we all know it was used by Rolex in the Daytona.Now the Zenith calibre 3019 was first introduced in 1969 and I'm pretty sure if there were any problems with hi-beat movements, 47 years is long enough for them to manifest themselves.Now introduction of the Rolex in-house cal 4130 in 2000 was ground breaking for Rolex as it was there very first chronograph movement in-house made.And as turned out to be IMHO in the top 5 of all chronograph movements made to date.

Ulysse Nardin marine chronometers have always been highly regarded but it is a little known fact that for years, they were fitted with a high-beat (36000bph) version of the ETA 2824-2, UN calibre NB11QU. Zodiac produced at least four high-beat movements from 1971-73, all with Albert/Shine ebauche, and fitted to the "SST" models. Longines experimented with calibres 430 to 433 from 1967 but when they introduced twin-barrel movements in 1975, chose to revert back to 28800 bph,and in these days Longines made some excellent in-house made movements to equal or better most.

Changing the subject slightly, the Longines twin-barrel movements were something I wish had survived in current production,a brilliant movement,but very expensive to make. Calibre 890, 892 & 893 had stacked twin barrels whereas calibres 990 to 994 had side-by-side barrels in a movement only 2.95mm thick. The power reserve of around 44-50 hours was respectable but not particularly impressive for a twin-barrel movement, although I'm sure that if R & D had continued on this movement this would have been substantially improved.And would have put many a modern movements to shame,from any manufacturer or brand even Rolex.

Now the main advantages of slower beat rates (18,000 , 19,800 and 21,600 ) are less immediate. Lower power needs allow for softer mainsprings, limiting stress and friction throughout the wheel train, winding train, and the escapement. Service intervals are longer and more flexible, and part wear replacements are negligible.But in general low beat movements will generally not perform as well as a fast-beat one, and while slow beat movements can perform very well it requires more skill and effort from the watchmaker to achieve and Rolex achieved that though the many years, through laborious positional adjustments and high quality movement parts . Now slow-beat is used primarily by manufactures of high-craft movements, most of whom consider today 21,600 BPH to the best.But most of these type of movements say Patek made being quite delicate and can easily be put out of adjustment by the slightest Mal adjustment like say a small fall or big shocks.


Some of the advantages of fast-beat (28,800 v/h and 36,000 v/h) are obvious, better isochronism, and better performance in both vertical and horizontal positions even with minimal adjustment or no adjustment at all.This is one of the reasons fast-beat has been almost universally adopted by mass-producers.If you think of a how fast a quartz movement beats,while Mechanical watch usually have 28000 to 36000 beats per hour, and therefore cannot compete with quartz watches that have around 4000 to 8000 beats per second (10 times faster).So in theory the mechanical High beat movement should be more accurate,with very little difference in over all power reserve, because they use a much stronger main spring.Now some say there is the possible extra wear factor in the Hi beat movement,but IMO as long as the recommend services are done,there is little or no difference,service is very important with any mechanical movement.

Now when Rolex's did the modification to the Zenith chronograph, where in addition to reducing the beat rate, they discarded the regulator and installed there own vastly larger Microstella balance wheel,and regulator.And when Zenith would not,or could not, supply the vast quantities Rolex needed, they was forced to design there first ever chrono movement the cal 4130 in 2000.

This is short list of outstanding movements that should all easily achieve a daily consistency of five seconds or better on the wrist.All of the current Rolex calibers including the Cal 4130 this a outstanding chronograph movement with a excellent power reserve and one of the best around now. But there are many others in the same class accuracy wise but less power reserve.

The ETA 2892-A2, ETA 2824/2T chronometer grade, ETA Valjoux 7750,Unitas 6497/8,Omega 2500, JLC 889/2 , JLC 960, Longines 990 (Lemania 8815), PP 215, PP 240,now IMHO the Grand Seiko 430 is one of best movements ever made .Others like the Zenith 400,Zenith 670, GP 3100 all excellent movements, plus there are many more.Would not call any modern movement made today best,whats best in one persons eyes is better in another's.But most movements today even from Alpha to every day Seiko, Miyota and all the high end brands all have there place in today's horological world.