Strap for Excellence Le Régulateur 39 Louis Erard x Konstantin Chaykin

The lug width of the Louis Erard Excellence 85248AA89.BGA091 is 20 millimetres. This measurement, expressed as the distance between the inner lugs that hold the strap, is the technical specification determining aftermarket strap compatibility. Correct measurement: position a digital calliper on the inner shoulder of the right or left lug, excluding the pin thickness, and read the value to the nearest millimetre.

For the 85248AA89.BGA091, we recommend an alligator or shell cordovan strap for formal wear (dark brown, burgundy, or black tones); vegetable-tanned calf leather for refined daily use; NATO or rubber for sports environments or summer wear. The choice depends on predominant usage context: the strap must complement the classical elegance of the 39mm case without visual overload.

Strap replacement requires no watchmaking expertise. Position the watch on a soft surface, use a springbar tool (lever or bifurcated needle instrument) to gently push the pin in one direction, extract the metal pin from the lug, remove the old strap and insert the new one by aligning the pins. Reverse the operation for attachment: the pin must enter completely with an audible click, without forcing.

Nearly all standard 20mm straps are compatible with the Louis Erard Excellence 85248AA89.BGA091, provided the external diameter of the pins (typically 1.6–1.8 mm) matches the watch pins. We recommend always verifying the technical specifications of the strap before purchase, as non-standard dimensions could create lateral play or insertion difficulties.

A high-quality leather strap (alligator, calf, shell cordovan) with vegetable tanning has a lifespan of 3–7 years of daily use, conditional on climate, humidity levels and maintenance. A rubber strap lasts 10–15 years. A NATO strap in nylon resists degradation for over 10 years. Longevity depends on UV exposure, relative humidity and cleaning frequency: storing unused straps in dry, cool environments significantly extends useful life.