Monochrome Watches
An online magazine dedicated to fine watches

Sinn R500 “Bullhead” Racing Stopwatch

An iconic 1970s Bullhead design for Sinn’s racing wrist stopwatch.

| By Rebecca Doulton | 4 min read |
Sinn R500 Bullhead Chronograph

Sinn, the German watchmaker with a forte in instrument watches, revisits a racing stopwatch from the 1970s complete with the historical “bullhead” design. Although this new model takes its design cues from a vintage and original chronograph, the Sinn R500 Chronograph is made from contemporary high-strength titanium with racy design features. A stopwatch designed for the wrist, the overall look of the R500 evokes the exciting atmosphere of motorsports. 

Instrument watches for extreme conditions

Sinn was founded in Frankfurt, in 1961 by Helmut Sinn, an instructor for blind flight (relying exclusively on instruments for flying an aircraft in conditions of zero visibility) and a former WWII pilot. The core business under Helmut Sinn was the manufacture of navigation clocks and pilot chronographs. In 1994 the company was bought by engineer Lothar Schmidt who pushed technological development to create reliable, ultra-resilient instrument watches, often for special forces – including Germany’s commando frogmen force (KSM).

Renamed Sinn Spezialuhren, the brand has set new standards in the industry with the development of countless technologies including Ar-dehumidifying and anti-fogging technology on dive watches (Hydro), temperature-resistant special oil technology to withstand temperatures of -45ºC to +80º, non-lubricant Diapal technology, ultra-hard Tegiment technology to reinforce steel cases, and even the co-development of a new technical standard for pilot watches known as TeStaF in 2012 (which would become the basis of the DIN 8330 standard). Countless design prizes and testimonials from arctic explorers, extreme athletes, pilots and divers attest to the solid technology and distinctive styling of this successful German brand.

Ad – Scroll to continue with article

Bullhead Stopwatch

Instrument chronographs, vintage-style and contemporary, are well represented at Sinn and range from highly complex navigation chronographs to rally models and from split-seconds to pilot chronographs. However, the new Sinn R500 is unlike anything else in the collection. With its distinctive 1970s “bullhead” case – a name given to this style of watches with the crown at 12 o’clock flanked by two push-pieces (horns) at 11 and 1 o’clock – the R500 immediately catches your eye. Popular in the 1970s, brands like Omega, Breitling and even Seiko and Citizen had bullhead models. Bullheads were essentially styled like classic stopwatches but attached to the wrist. To enhance operability and legibility, the cases of these watches were often sloping – thicker at the top and slimmer at the bottom. Angled towards the wearer, reading elapsed times was easier and the chronograph push-pieces at the thicker top part of the case were also easier to access and manipulate.

Sinn R500 Bullhead Chronograph

The 42mm case of the Sinn R500 is made from high-strength Grade 5 titanium with a sporty matte brushed finish. This choice of this material underscores the technical and more contemporary interpretation of a Bullhead model and ensures a comfortable fit.

Sinn R500 Bullhead Chronograph

Viewed from the side, it is easy to appreciate the marked inclination of the case. The thickness of the case at 12 o’clock is 16mm, at 6 o’clock 13mm. The solid yet lightweight case (74.5g without strap) features a screw-down caseback ensuring the 200m water-resistance.

Racing instruments

Set against a matte black background, the white markings and creamy counters on the dial pop out vividly. The tachymetre scale to 500  km/h – a must-have on a racing-inspired watch to measure speed – is relayed on the interior bezel and the fuel gauge, or power reserve of the engine is in a prominent position at 12 o’clock picked out in an arc in green and red. The three sub-dials are a creamy beige colour with snailed interiors and clear black markings (12-hour counter at 3, 30-min counter at 9 and running seconds with date window at 6 o’clock). The rectangular indices are applied, and like the hour and minute hands, are all treated with white luminescent paint that glows green in the dark. The central seconds chronograph hand is black with a bright red arrow tip.

Sinn R500 Bullhead Chronograph

The Sinn R500 comes with a sporty black cowhide strap with red stitching integrated into the case and features the classic aerated pattern (holes) associated with the world of car racing.


The Sinn R500 relies on a Valjoux 7750 automatic chronograph movement beating at a frequency of 28,800vph and providing the watch with a 42-hour power reserve. Anti-magnetic to German DIN 8309 standards (ISO 764) of 4,800 A/m, the movement incorporates a stop-seconds function.

Availability and Price

The Sinn R500 “Bullhead” Chronograph is limited to 300 pieces and can be ordered on the brand’s webpage. The retail price is EUR 3,950 (incl. tax). Shipping costs apply outside Germany.

More information at Sinn.

Leave a Reply