Omega
Speedmaster Broad Arrow 3659.50.31— lug 20mm

The Speedmaster Broad Arrow 3659.50.31 in red gold features a lug width of 20mm. This measurement is specific to this model and remains a robust standard in the aftermarket strap offerings, ensuring constructive variety and access to premium materials.

For the 3659.50.31 in red gold, we recommend cognac or tobacco alligator for natural aesthetic continuity, or bordeaux shell cordovan for excellent patina density. Both materials complement the warmth of red gold without chromatic competition. For formal occasions, vegetable-tanned calf leather in dark black offers calibrated contrast and reduced maintenance.

Changing the strap on the Broad Arrow 3659.50.31 requires a spring bar remover to extract the elastic pins from the lugs. Position the remover under the pin, apply light and steady pressure to open the spring, then remove the old strap. Insert the new strap by aligning the holes with the pins, press until they click. Caution: do not force rotational movement of the lugs—the 20mm dimension remains stable and pins must slide vertically. If the pins do not click, verify that the strap is actually constructed for 20mm by measuring the internal lug distance.

A strap correctly constructed for 20mm remains fully compatible with the 3659.50.31 without any modifications. The original lugs maintain standard tolerances: any strap measuring 20mm between the housing holes will fit perfectly without vertical or lateral play. It is not necessary to file, sand, or adapt the strap. If you encounter insertion difficulty, the problem lies in the strap's constructive calibration, not the Omega case.

The lifespan of a premium leather strap (alligator, shell cordovan, vegetable-tanned calf) under daily wear ranges from 3–5 years depending on use and climate. The Omega Speedmaster Broad Arrow 3659.50.31, being a robust chronograph, tends to undergo frequent mechanical activations and thermal stress: we recommend rotation with alternative straps to distribute wear. Maintenance: promptly dry accidental wetting (it is not water-resistant like the case), avoid prolonged exposure to direct heat sources, condition with specific balms every 18–24 months. Natural patina remains an element of constructive beauty, not degradation.