Originally known as the “wristwatch with double stopwatch,”  no one could have predicted the rise of the now-legendary 158 pilot chronograph. Back in the 1980s and early 1990s, it wasn’t a bestseller. As with many classic models, it needed more time.  Among collectors, it is now one of the most sought-after watches ever produced by Sinn.

Behind every good watch, there seems to be an equally good story. The origins of the Sinn 158 are so unusual because the model’s predecessor wasn’t born in the Sinn factory at all. Nowadays, it is commonplace to assume nothing but vertical production. But the meandering past of the watch industry often has a historical treat in store, if only you dig deep enough.


Model 155 Bw

In the years from 1967 to 1981, the Bundeswehr (the German armed forces) replaced the military chronographs of domestic manufacturers (Hahnart and Junghans), which were no longer available, with flyback chronographs from Heuer-Leonidas SA 1550 SG. Many watch lovers will have heard of that company before (especially by its shortened name, Heuer 1550 SG). Its association with the Bundeswehr, however, is not as well known.

When the Bundeswehr again changed suppliers, Helmut Sinn purchased the discontinued Heuer-Leonidas inventory from the military. Sinn reconditioned these watches and added its brand name to the dial. The Valjoux 230 hand-wound chronograph movement ticked away inside these impressive watches, and a rotating pilot’s bezel completed the package. Sinn cataloged this model as the 155 Bw and marketed it under the label “Bundeswehr Chronograph for Pilots.”


Traditional pilot chronographs

The design of the traditional 158 pilot chronograph is in-keeping with that of its predecessor. The 43mm bead-blasted case, the high-domed acrylic glass, a black, easy-to-use pilot’s bezel manufactured from anodized aluminum, and a large, equally comfortable winding crown, which is distinctly reminiscent of our traditional pilot chronographs.

Thanks in part to the unusual, two-ply case construction of the Sinn 158 chronograph, the watch is able to withstand very low pressures as well as high pressure up to a 10 bar rating. While many watches use a single-piece case middle, the Sinn 158 does not. Instead, the movement is housed in a core capsule. This is surrounded by an outer case sheath sporting lugs and a bidirectional pilot’s bezel.


The movement

Powering the new Sinn 158 chronograph is the trusty automatic SW 510 caliber, supplied by Swiss manufacturer Sellita. The dial-side configuration of this movement enables a handsome bicompax display. Additionally, the design remains true to the historic model. The going seconds are displayed at 9 o’clock, while the chronograph minute register is located on the other side of the dial at 3 o’clock.

Providing visual balance with the company wordmark is a date window at 6 o’clock. Its placement gives the dial a subtle sense of completeness. It does this without distracting from the important information displayed by the chronograph function. To ensure optimal legibility, the chronograph seconds and minute hands are brilliant red. A luminous white compound coats the numerals, and hour and minute hands. This improves legibility in low-light conditions.

Sinn will produce just 500 of these 158 pilot chronographs. Limited-edition engravings will decorate each case back. To learn more about Sinn, check out the official website here.