Collector’s View: Paul Gerber Cal. 41 – the seconds in your hand

Paul Gerber is perhaps the most subtly ironic watchmaker – always ready with a charming watchmaking twist – such as this ‘bi-nique’ Cal. 41 wristwatch with switchable jumping/permanent seconds and triple rotors


Today I’d like to feature a very special watch made by an exceptional watchmaker, the Cal. 41 Switchable Jumping/Permanent Seconds with Triple Rotor by Paul Gerber. It is believed that only two of these watches were ever made.

A watchmaker of legendary repute

He is a man of ample experience, a man who needs no real introduction here, one of the legends in watchmaking: Paul Gerber from Zurich.



In 1989, Paul started originally with a miniature wooden clock (‘since wood is easier for me to work on, back in the days’) which jump-started his unchallenged reputation as the ‘master of the non-existent space’:

(Paul Gerber’s first clock ever from 1989; the ‘Kuhschwanz-Augenwender’, English ‘cow-tail eye-mover’, named after the pendulum shape and the fact that the boy moves his eyeballs. The pencil serves comparing sizes)

This reputation enjoyed another boost with the completion of the Superbia Humanitatis, an ultra-complicated watch that according to the ‘Guinness Book of World Records’ is the most complicated wristwatch in the world. This, at least, is true as far as unique pieces are concerned.

(The Superbia Humanitatis on the wrist of its creator; its highly complex movement)


Yet exotic or stratospherically elevated watches are not all he does: famous as well are his retrograde seconds indications, and here again Paul Gerber was the first one to implement. He used a stock ETA Peseux 7001 movement and transformed it first with a retrograde seconds indication and a bit later with an automatic winding system.

And what a system it was! Puzzling for many at first view, with its twin rotors that had overlapping radii, yet somehow never bumped into each other… these two rotors gave the watch its name: Retro twin:




Paul also developed a great number of constructions for other brands, such as the alarm complication into the Valjoux 7750 for Fortis.

More recently, having passed official retirement age in Switzerland, Paul Gerber takes the freedom to work only on projects which satisfy him, and devote more time to fostering the knowledge of watchmaking, particularly through the immersive hands-on course for collectors:


(Paul Gerber teaches his workshop participants how to heat-blue screws)

Combining favourites, in-house style: Cal. 41

Seconds and multiple rotors – these bring us to the watch I want to present in this article: the Cal. 41. This watch refers to Paul’s second in-house movement (after the Cal. 33 form watch using his own proprietary escapement, perhaps a topic for the future…), a comparatively large automatic movement with 100 h autonomy (thanks to two barrels) and a 21,600 A/h balance.




Again, the immediately striking features are not only the fine finish with matt surfaces and hand-anglaged edges, but again the rotors – three of these, and again they magically do not touch each other.


(Solid golden rotors reside atop a finely finished movements. Note the polishing and the matter surfaces. Top right above the balance cock you’ll note some levers for the switchable seconds display – see further down!)


The surprising (-ly simple) yet absolutely logical reason for this is a central command instance: the large wheel in the centre coordinates the triple rotors and fixes their relative position via the large central wheel. This way, they can never bump into their siblings, the same principle already employed with the Retro twin. The rotors wind in both directions, btw.


(Each of the rotors has its own small ball bearing and meshes into the large central coordinating wheel. Left, production version main plate with custom-made ball bearings; right prototype with smaller commercial bearings)

The seconds – at your command, Sir!

But the Cal. 41 has – upon custom order – another ace in its sleeves: The central seconds hand can smoothly move permanently or jump in seconds interval just like a quartz watch. All this switchable just as the owner prefers it.

In normal production watches such change in operation is controlled by a pusher at 2 o’clock, while the very watch I present here can achieve this with a simple push on the crown. A second push on pusher or crown respectively, return the original state.

Its really worth watching this live: