F.P Journe Chronometre Optimum  CO PT 40 A SI

Our first FP Journe review on the channel so we’ll cut the foreplay and dive right in to the watch.

This is the F.P Journe model that is dedicated to super precise timekeeping. 

First launched in 2012 it has been a constant in the collection for over a decade. 

Quick stats - Platinum, 40mm diameter but wears a little larger as its “all dial” with a slim bezel, 10mm thick and 30m WR. 

20mm lugs so a nice standard size for those who like to play with straps, but do remember to arm yourself with curved spring-bars as the lugs are drilled close to the case which is aesthetically pleasing but tricky to deal with unless you’ve got the right gear. 

The dial is full of information without being cluttered. The base is white gold, with applied stainless steel frames surrounding the main body of the dial and small seconds sub-dial. 

I think its a nice touch using inner arabic hour markers with the minute track numbered around the outer dial as well. Both nicely set off with some guilloche in the centre. 

Flame blued hands add both a bit of fancy plus excellent legibility against the cream backdrop.

The window at 10 offers viewing of the “remontoire” a movement feature designed to stabilise the accuracy of a watch, hence its inclusion as a complication in the “Chronometre Optimum” 

A watch is powered by a mainspring housed inside a barrel that delivers power to the balance spring which is attached to the balance wheel. 

The balance wheel is responsible for controlling the speed at which the wheels powering the hands etc turn.

As a mainspring unwinds, it can lose power, particularly in hand wound watches. 

Less so in autos as they keep themselves “topped up” by motion. 

This loss of power can disrupt timekeeping as the wheels powered by the springs slow down, similar to the way in which an electric shaver slows down its cutting speed before eventually grinding to a halt. 

The same thing happens in reverse when a watch is fully wound and the mainspring is putting out more power, things speed up. 

A remontoire (from the French word remonter, to wind) is a secondary spring added to the movement that provides stable power to the balance mechanism. 

It regulates the power delivery between fully wound and unwound. 

Effectively - constant force applied to the balance and escapement courtesy of a remontoire = stable timekeeping that isnt affected by a loss of torque, or as FP calls it “optimal chronometry”

There’s an indicator at the 7 area of the dial for you to keep an eye on the manual movement and wind when required. 

Note that all power reserve indicators on FP Journe chronometers are in REVERSE.

0 indicates full power (zero hours since last winding) and the reserve ticks down into the red zone. This movement actually delivers 70 hours on a full wind but FP have denoted “optimal” power on the reserve which much like a petrol gague doesnt count the dregs left in the engine. 

If you flip over to the back of the watch, above the remontoire sits another seconds counter. This one shows “dead” seconds (incremental ticks like a quartz) when the watch is operating on full power, and drops to a sweep seconds display when at low power. Its another way of checking that the remontoire is doing its business in the back. 

Speaking of back business, the calibre 1510 is made from 18 carat rose gold which is rare. 

This may be a “time only” piece but it is full on high horology.