Strap for Lyre 40 Automatic Stainless Steel / Silver / Bracelet

The lug width of the Longines Lyre L4.961.4.72.6 is 21 millimetres. This dimension, rare in contemporary watch catalogues, is specific to Longines models of that generation. To verify with precision, position a digital calliper or millimetre ruler perpendicularly against the case lugs, measuring the internal distance. An error of half a millimetre compromises strap compatibility.

For this brushed stainless-steel 40 millimetre case, alligator represents the maximum elegance choice, featuring fine regular grain and an ideal thickness of 1.6 millimetres. Vegetable-tanned calf leather offers a more accessible formal alternative, with a thickness of 1.4–1.5 millimetres to avoid visual overloading on the dial diameter. A vulcanised rubber strap adds sporting versatility without technical compromise, maintaining consistent shape over time.

Remove the worn strap using a dedicated tool (spring bar tool) to extract the spring bars from each lug of the case. Rest the watch on a soft surface (microfibre cloth) to prevent scratching. Insert the new 21 millimetre strap into the lugs, ensuring the strap aligns perpendicularly with the case. Press the spring bar and insert the pin with deliberate pressure until you hear the locking click.

Yes, provided they are explicitly manufactured for a 21 millimetre lug width. Universal or standard straps (20 millimetres) are unsuitable: they generate overly wide passages, misalignment, and unwanted case movement. Always verify the specific 21 millimetre dimension before ordering online. Custom artisanal straps offer maximum compatibility and construction quality.

A quality alligator or calf strap, subjected to ordinary use and regular maintenance, has a service life of 3–5 years before requiring replacement. This interval depends on frequency of wear, sunlight exposure, humidity, and leather care. A vulcanised rubber strap retains physical properties for 5–7 years. Store the strap away from direct sunlight and excessive humidity; occasionally apply a natural leather conditioner to preserve flexibility.