Speedmaster Sapphire Sandwich : the 3873.50.31

Omega Speedmaster Professional 3873.50.31

Omega Speedmaster Professional 3873.50.31

With the news of the updated Speedmaster Professional references and price increase, we thought a post regarding a ‘old’ Speedy Pro would be fitting. Our choice for today is one we’ve written very little about – the Speedmaster sapphire sandwich on alligator, the Speedy Pro 3873.50.31.

While most aficionado’s prefer the classic 3570.50.00 (to be replaced by the 311.30.42.30.01.005), there is something to be said for the Speedmaster Sapphire Sandwich. The increased heft, the possibility to admire the movement in all its glory and the scratch-proof crystal all are valid point which may sway one towards the 3873.50.31 – soon to be replaced by the 311.30.42.30.01.002.

Omega Speedmaster Professional 3873.50.31

Omega Speedmaster Professional 3873.50.31 caliber 1863

A bit of background: the Speedmaster Sapphire Sandwich got its nickname by having a sapphire glass on both the front as well as the back, while the classic Speedmaster Professional uses a hesalite (plexi) crystal and a closed caseback. It is fitted with caliber 1863 instead of the 1861 used on the Speedies with closed back.

The difference between the 1863 and 1861? The latter uses the ‘Delrin‘ (nylon) chrono brake, while in the former this part is executed in stainless steel. In the picture above, it is the part held by the bigger screw beneath the three brass coloured gears. It is said that the Delrin brake was introduced (in 1974) to enhance reliability, but in real life an advantage to either side is more of an academic question – we’d love to hear how many timing operations need to be performed for an opinion to slide to the 1861 in favour of the 1863 or vice versa. Omega simply reintroduced the metal brake for more visual appeal for Speedmasters fitted with a see-through caseback.

Side note – while the bracelet is the obvious choice, the Speedmaster looks great (and chic) on alligator!

Check out our preferred AD Ace Jewelers for the latest pricing on Speedmasters.