Strap for Gravity Earth

The Armin Strom Gravity ST13-GE.90 is fitted with a 20mm lug width. This dimension is compatible with the compact architecture of the 43.40mm case and allows the use of any standard aftermarket strap with 20mm lugs. Always verify compatibility by measuring the internal distance between the lug pins before purchasing a replacement strap.

For the Gravity ST13-GE.90, we recommend a dark alligator strap (brown or black) with fine grain, which emphasises the technical elegance of the visible movement. A vegetable-tanned calf leather strap represents the premium alternative, developing authentic patina over time. For a sportier variant, a NATO strap with tight weave creates aggressive contrast. FKM rubber is ideal for humid environments whilst maintaining overall aesthetic quality.

Changing the Gravity ST13-GE.90 strap is accomplished via two spring bars (screw-operated bars) located laterally at the lugs. Use a dedicated tool (spring bar removal fork) to compress the internal spring of the bar and extract it. Position the new strap, reinsert the bars, and verify they enter deeply into the attachment hole. Do not force: correct insertion is smooth and effortless.

Yes, any strap with a 20mm lug width is compatible with the Gravity ST13-GE.90. However, we recommend selecting thicknesses coherent with the case mass: 2.5mm to 4mm for leather, 3mm to 5mm for rubber. Avoid straps that are too thin (under 2mm) as they would visually diminish the case diameter; discourage excessively rigid straps that alter the wearing position.

A quality leather strap (alligator, vegetable-tanned calf) lasts 4–7 years with moderate daily use. Durability depends on UV exposure, humidity, and frequency of wear. Natural leather ages visually over time, developing authentic patina. We recommend applying a protective balm every 12 months and avoiding repeated immersions. A NATO strap lasts 8–12 years; FKM rubber 5–8 years with proper maintenance.