We’ve already seen the Chronostop with the 865 movement earlier. Charles sent this one in for a service. It does look like it could do with a bit of TLC, so let’s administer that.
The top plate of the 865 and the 920 are identical, as the difference is the date on the bottom plate.
The movement can do with a service; the amplitude is rather low.
One of the case clamps is broken, but I can find a new original one.
Time to take the movement apart.
Under the chronograph layer is the wheel train.
The usual dirt.
Check out the mainspring – somebody shortened a broken mainspring and bent a hook so it would stick to the barrel.
Now for the difference – the 920 has a date display.
The chronostop movement is pretty complex, and has almost as many parts as a proper chronograph.
That looks better than the cobbled together old mainspring.
I start off with the wheel train.
And the base movement is ticking again.
Now that’s better!
Now it’s time for the chronograph layer.
The bottom plate ready for dial and hands.
The second hand had a split tube, but I managed to find a new one, and everything is working again as it should.