Patek Philippe Ref. 5200 Gondolo 8 Days, Day & Date Indication – Ron DeCorte

Patek Philippe introduces a different twist to a proven platform, Patek Philippe Ref. 5200. In 2000, Patek Philippe launched limited edition Ref. 5100, a 10-Day manual wind rectangular watch with power reserve. In 2003, the same basic platform was employed on the 10-Day Tourbillon.

Replica Patek Philippe Ref. 5200 shares some important legacies with its immediate predecessors. Eight days of power reserve, power reserve indication and style, classic style. Its personal contribution to the trio is an instantaneous day-date calendar made possible in an extended power reserve watch via twin mainspring barrels and Silinvar® escapement innovations.

Looking from the dial side it might seem that everything looks the same. Not so, when we start investigating under the dial and between the plates and bridges, the similarities end.

1. 10-Day Tourbillon, Ref. 5101P, 2003

2. Gondolo 8 Days, Day & Date Indication, Ref. 5200G, 2013

3. 10-Day, Ref. 5100P, 2000


Although all three watches share the exact same power train configuration, the Ref. 5200 comes up short by two days. Allow me to explain. The Fake Ref. 5100 10-Day and Ref. 5101 10-Day Tourbillon enjoy relatively simple mechanics that are not as power hungry as a day-date calendar. Refs. 5200, 5100 and the 10-Day Tourbillon all incorporate a power reserve indicator which consumes extremely little power consistently over the course of the day and week. While calendar mechanisms’ must accomplish the major feat of shifting the day-date indicators each day, thus requiring much more mechanical energy.

A simple day-date mechanism (semi-instantaneous) requires much less energy for most of the day, but as midnight approaches, it faces the challenge of changing both the date and day indications in a tenuous and unsynchronized process.

An instantaneous calendar mechanism on the other hand faces this challenge casually over the course of the day by slowly building the necessary energy via a cam, releasing its energy and shifting both day and date indicators precisely, instantly and in perfect harmony.

Silinvar® plays an equally important part in making Ref. 5200 possible. Spiromax® hairspring and Pulsomax® lever and escape wheel are all Silinvar® innovations and I’m certain these innovations are important horological contributions, even if they run contrary to the naysayers.

Pulsomax® brings oil-less escapements to the forefront. The efficiency (lack of friction and mass) of two Silinvar® components, escape wheel and pallet fork, is immensely important allowing Ref. 5200 to beat at 4hz with ease.

Spiromax® would not be possible without Silinvar®. There is no other current possibility of constructing hairsprings with such geometric and chronometric precision.