Strap for Motorsport Automatic Chronograph PVD / Carbon Bezel / Black / Limited Edition / Rubber

The lug width of the Formex Motorsport 3100.9.8299.910 is 25mm. This unconventional dimension reflects the proportions of the 46.50mm case and requires a strap constructed to specific technical specifications. We recommend verifying the tolerance with a digital calliper: the acceptable range is 24.8–25.2mm to ensure correct spring bar insertion.

Alligator leather with vegetable tanning is the ideal choice for this racing chronograph. The natural grain of the back and progressive patina amplify the technical character of the watch. Alternatively, English calf offers understated elegance, whilst for more intensive use a NATO in ballistic cordura or gummed caoutchouc delivers durability without functional compromise.

Position the watch with the dial facing downwards. Locate the spring bars at both ends of the case. Using a dedicated tool or small screwdriver, press the spring bar towards the centre to disengage it from the lug shoulder. Remove the used strap and insert the new one by aligning the holes with the spring bars. Verify that the spring bar clicks correctly: it must be positioned vertically relative to the lug shoulder.

Yes, all straps from Milano Straps' 25mm collection are custom-built for the Formex Motorsport 3100.9.8299.910. Each strap is handcrafted with precise tolerances (24.8–25.2mm) and undergoes quality control before dispatch. You can personalise online by choosing material, colour, buckle type and stitching.

An alligator strap with vegetable tanning, used regularly, has an estimated lifespan of 3–5 years before requiring buckle repair or replacement. Longevity depends on frequency of use, exposure to moisture and maintenance. A NATO or gummed caoutchouc strap resists longer in aggressive environments. The patina that develops is a positive characteristic, not a defect.