Prior to re-assembly I notice another issue: the third wheel has a bent pivot. With all of this completed the balance assembly is ready to be put back together and to be cleaned with the rest of the parts. Once this was done, I remove the hairspring from the balance, and further tweak the spring to ensure the collet is perfectly centred with the axis of the balance wheel. Mainspring repairs are particularly tricky, but there was little to lose in this case, so I manipulated the hairspring to make it sit in a plane parallel with the balance again. The hairspring is out of truth and is rubbing against the balance bridge, hence the very fast rate Silas observed during use: this drastically reduces the effective length of the spring. There are signs of previous manipulations of the hairspring, which clearly were unsuccessful! The antishock settings and jewels are also stripped down to give them a proper clean in the ultrasonic machine.ĭuring the strip down, I figure out why the watch is performing so poorly. I soon have the whole movement stripped out ready for inspection of the parts and cleaning. The jewel on the balance is retained by a pivoting arm, very novel indeed, but quite easy to work with. You can see the two anti shock settings and springs on the escape and balance wheels, an interesting and different approach to shock resistance devices.Īnd taking another look at the upper side of the movement, you can now see the two anti shock devices on the balance and escape wheel. We can now take a look at the lower side of the movement after removal of the dial and hands. Instead it is driven “outside the train” by the third wheel. In simple terms this means that the seconds pinion is not transmitting power from the mainspring to the escapement as part of the train of wheels. As you can see it is an indirectly driven sweep second design, the wheel driving the sweep seconds pinion is mounted on an extended pivot of the third wheel. Opening the caseback reveals the very nice Cyma R.459 movement. I placed the Cyma Navystar on the timegrapher before commencing the service, and I could not get a reading, so something was not right. The watch is powered by Cyma’s calibre R.459, which uses the interesting antishock device called “Cymaflex”, more on that later. He reported very poor timekeeping (about 20min/day fast) and the crown did not sit flush against the case, so the watch was definitely in need of attention. Silas sent me this rather lovely Cyma Navystar watch for a service.