Sinn logo.jpg (2557 bytes)


sinn903top.jpg (48670 bytes)

(picture from Internet, source unknown)

This watch’s history:

Even before I got my Sinn 656 Fliegeruhr, I was looking for this Sinn 903. Not the modern automatic version with the Valjoux movement, but the older handwind version, with the Lemania 1873 movement. They were no longer available directly from Sinn in Frankfurt, but every now and then they appear for sale on the Internet.

Why did I want a Sinn 903 with the Lemania 1873 version of this watch? Well, it's like getting 2 watches for the price of 1. I love the Omega Speedmasters, and I already had a 1965 model 105.003. That Speedmaster's got the famous Omega cal. 321 movement inside. (also based on a Lemania movement) I also wanted a Speedmaster version with the Omega cal.861 movement (based on the Lemania 1873)

But I also liked the Breitling Navitimer. When I found out about the Sinn 903 I decided to go for that watch.

Another advantage was that the Sinn 903 was much cheaper than the Breitling Navitimer, and also cheaper than the Omega cal.861 Speedmasters.


Brand and Reference:

For info of the Sinn brand and the man who started the company, Helmut Sinn, see my review on the Sinn 656.

This model, the 903 has got a very interesting background. In 1979 the Breitling company went bankrupt, and parts of the company were liquidated. Mr. Helmut Sinn bought the rights to use the dial lay-out of Breitlings 806 and 809 Navitimer watches. This explains the resemblance with the Navitimer. So the 903 is not an illegal rip-off version, but Sinn still owns the rights to produce these watches. Interesting is that the Ollech&Wajs company bought many of the Breitlings spare parts, machinery and hardware. O&W still manufactures legal Navitimer look-alikes under the brand name Aviation. Later on in 1979 Breitling was sold to Mr. Ernst Schneider, and now Breitling is back in business as never before.

Sinn also had the rights to produce a Navitimer style watch, now they needed a movement in it. They needed a movement with the so called "tri-compax" lay-out. That is where the subdials are located on the 3, 6, and 9. They found such a movement, the proven Lemania 1873, witch also served as the base for the Omega Speedmaster Professional starting in 1968. The 903 sold for a mere 1100 Euro's. Far under the price of a modern Omega Speedmaster (2220 EURO for the basic model 2003 price) and of the modern Breitling Navitimer (3450 EURO for the basic model 2003 price). The 903 was loved not only because of it's price. But early 2000 Lemania decided only to sell the 1873 movement to sistercompanies of the Swatch Group. I got an e-mail from Sinn that the 903 with Lemania 1873 movement sold out in september 2001. So Sinn had to look for another movement, they found it in a modified automatic Valjoux 7750 movement. This model is still sold today.




The Lemania 1873 is a classic chronograph movement. It has proven it's reliability for a long time now.  The diameter of the movement is 27,5mm and it is 6,87mm in height. 17 jewels, 21600 A/h, and a power reserve of 50 hours. It is made out of 221 different pieces. The movement can be seen through the display back of the Sinn 903, and I must say, it's a lovely sight. As can be seen in the picture there is a synthetic part in the movement. I know Omega replaced this synthetic part in the display back version of the Speedmaster purely for aestetic reason. Sinn used both with and without this part for the 903's. Mine is with the synthetic part. Engravings on the movement are: "LEMANIA", "SWISS SEVENTEEN 17 JEWELS", "UNADJUSTED", the movement number "1441479" "1873" and the Lemania factory stamp.




sinn903 side.jpg (43500 bytes)Case, crown and crystal:

The case of the watch is 41mm in diameter, and the watch is 13mm in height. It weights 68 gram case without any strap or bracelet.  The crown is signed, unprotected, and not screwed. The chrono pushers function good, and to start and stop timing a firm push is needed. The bezel can be turned in both directions, this is needed for the slide rule calculation functions. The grip on the bezel is very good, and turning the bezel is smooth but not too loose. Lug width is a whopping 22 mm !!! The crystal is domed mineral glas. It is attached to the bezel, so the glas also turnes when you turn the bezel. The whole construction implies that the waterresistance is close to zero. I guess a WR of 30 meters is stated by Sinn. No way I'm going to swimm or shower with this watch.




sinn903back502.jpg (35051 bytes)Back:


The back of the watch is see through with mineral crystal. (scratches easely). Thus the lovely movement can be studied. The back is pressed on the back, and this also does not help the waterresistance of the watch. Engravings on the back are: The "SINN" logo, "DIE NAVIGATIONSUHR", "ANTIMAGNETISCH", "STOSSICHER", "EDELSTAHL", and the number of the watch "9030320". Sinn could not tell me when exactly the watch was produced.







sinn903frontcut.jpg (93046 bytes)Dial and hands:


The dial is what this watch is all about. Like mentioned before this is a Breitling Navitimer style watch, featuring the slide rule bezel. With this bezel various calculations can be performed. The watch came with a "manual" on how to use the bezel for the different calculations. I'm amazed at what calculations can be done with the use of the bezel, but it takes more than a look at the manual to be able to reproduce the calculations. So practically I don't think a pilot would ever use this watch for calculations, but it gives the watch a nice "macho" look. Many people think this dial is too busy, but I love it. I will not get into detail on how these calculations are being done. The dial itself is "black like the sky on a moonless night" as Special FBI agent Cooper would say. At 9 is the small seconds subdial, at 3 is the 30 minute chronograph subdial, and at 6 is the 12 hours chronograph subdial. There's no date. The "12" is in Roman, the 1 through 11 are just markers. The Sinn logo is discretely placed at 12. At 6 in small print it says: "T SWISS MADE T", indicating that the markers are filled with Tritium for luminosity. But the luminosity is very weak.



Other Handwound Sinn 903's:

90312-24a.JPG (61592 bytes)Based on the Lemania 1877 movement is this 24-hour dial lay-out version of the Sinn 903. This version has the 12 hour indication at the top position.








90324-12a.JPG (57052 bytes)Also a 24-hour dial lay-out watch with the same movement (Lemania 1877). Only this version has the 24 hour indication at the top position.








Perhaps the rarest of Sinn 903 handwound watches is this 12-hour version with the Valjoux 7740 handwound movement. The tri-compax sub dial lay-out is different as on the Lemania based handwound 903's. The seconds sub-dial and the 12-hour counter have changed position. Also, this version has an extra function, a date window between the "4" and "5" o'clock position. The Lemania movement is so much nicer to look at.....

903hw7740.JPG (57816 bytes)903hw7740mov.JPG (39605 bytes)



You can not get a better deal for a Lemania 1873 movement. If you like this type of dial, forget the Breitling Navitimer, and go for the Sinn 903.

Unless stated differently, All of the pictures are of the actual watch, and the pictures are taken by myself, (I'm not a great photographer)

If you have any questions or remarks, feel free to e-mail me.

I have some watches for sale, to see the actual inventory of my watches for sale, see my little web-shop  Horlogerie Nivelacuso at