Thoresen Recipro-Register

A proper Landeron chronograph

Having repaired one of the oddball chronographs of the 1950’s, I now set my eye on a more conventional chronograph movement. My options, limited by my wallet, were confined to either a Venus, Valjoux, or Landeron calibre which were the most common of the period. There were others to be sure but the majority fell under these three Swiss manufacturers.

Landeron was the most economical of the three then and remains so now. The Landeron calibres (48, 148, 248) did not utilize the more difficult to manufacture column wheel switch and seems to have been made in larger quantities than the Venus and Valjoux chronographs; however, whereas you can find Venus and Valjoux movements in such watches as those sold by Breitling and Rolex, Landeron was employed in the lower end of the Swiss watch portfolio.


The Thoresen Recipro-Register is one of these watches. Thoresen appears to have been a department store or mail order business operating in the early 1950’s. The Recipro-Register was one of several branded watches sold by Thoresen which used Swiss ébauches. To this day, you can find copies of their advertisements online, even those featuring the Recipro-Register.

I obtained this piece from the Goodwill in fair condition. The watch functioned but ran fast and the sweep second hand did not return to the twelve o’clock position when operating the flyback pusher.

Good amplitude but not so great beat error

Upon removing the caseback I was a bit stunned to see the condition of the movement.  For a watch that was sold in the early fifties, this one is in great shape.

Dirty on the outside but pretty on the inside

Under the microscope it looks even better.

It looks even better under the microscope

I removed the watch from the case and the dial from the movement.

Not many dials of the era have aged as well as this one

The dial side of the movement is in wonderful shape too.

Dial side is in good shape too

I broke down the movement in short order and prepared it for a run through in the cleaning machine. A little water must have worked its way into the case through the openings for the pushers and stem as there is some discoloration on the plates and a few rusted bits of the keyless works require polishing with pegwood. All in all, the watch is in remarkable condition considering its age.

Ready for cleaning

Although the amplitude was good, the mainspring is old and will be replaced.

Old blued steel mainspring

A new spring is sourced and ready for the barrel.

Replacement spring ready for the barrel

Before assembly, the escape wheel, pallet fork, and cap jewels are treated with Moebius Fixodrop. The parts are placed in a basket and submerged in the solution for two minutes then drip dried for two more. After removing the basket from the bottle final drying occurs with a heat gun.

Fixodrop helps keep the lubricating oil from spreading within the watch. It acts a bit like a coat of wax causing the lubricating oil to bead and not run.

Some components are treated with Fixodrop

The gear train begins to come together.

There is a little bit of staining on the main plate

Then the dial side is assembled.

Dial side reassembled

Once the base movement is assembled it is ready for testing.

It’s hard to get that beat error down to zero

The results aren’t fantastic but they are an improvement and we are talking about a sixty year old time piece. I’ve been unable to eradicate the beat error and noted that a one of the pivot jewels for the pallet fork is chipped on the side of the oil cup. This should be replaced so I decide to revisit the beat error problem at that time.

I turn my attention to the chronograph layer and begin assembly. I work slowly testing the movement of each piece and applying oil and grease accordingly.

The chronograph works begin to come together

Once complete and operating properly I re-case the movement before installing the dial. It takes a bit of effort to properly set the chronograph hands as they must return precisely to the zero position when operating the flyback pusher but after about three tries I get it just right.

Re-cased and ready for the dial

Lastly, a new crystal is put in place. With the caseback refitted the watch is ready to wear (as soon as a new strap is procured).

My goodness it looks good with a new crystal!

Author: JPMoeller

Amateur watchmaker and California resident

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