Strap for Portofino Automatic Yellow Gold / White / Bracelet

The lug width of the IWC Portofino IW9251-01 is 18mm. This measurement represents the distance between the two attachment pins located at the ends of the case. To verify it, use a calliper to measure the internal space between the metal cylinders: it must be exactly 18mm. Any compatible strap must strictly respect this dimension.

For the Portofino IW9251-01 in yellow gold, the ideal strap is constructed from high-quality alligator with fine grain, or alternatively vegetable-tanned calf leather. Dark brown alligator (cocoa) creates harmonic continuity with the gold; black calf introduces formal contrast; cognac calf subtly dialogues with the warmth of the case. Avoid excessively casual materials such as heavy textiles or coloured rubber, which would result in excessive contrast with the precious nature of the timepiece.

To change the strap, you must remove the attachment pins—the metal cylinders at the ends of the case. Using a specialised tool called a spring bar tool, apply gentle downward pressure to compress the internal spring of the pin: this allows you to extract the cylinder from the strap lugs. Once the old strap is removed, insert the new one by aligning the lugs with the pins and releasing the spring bar tool. This is a delicate operation requiring careful attention: if you are not experienced, entrust it to a specialised workshop.

Yes, aftermarket straps are compatible provided they strictly respect the 18mm lug width. Online and through specialised artisans, you can find straps of superior quality to the originals, customised in leather, finishes and length. Milanostraps offers 18mm straps for the Portofino, customisable in size and details. For a bespoke experience, the Casati Milano atelier creates straps in its own workshop with personal selection of leathers.

The durability of a leather strap depends on usage and construction quality. High-quality alligator or calf leather, properly maintained, resists 3 to 5 years of daily use before requiring replacement. The patina that forms over time is a natural sign of ageing and adds aesthetic character to the strap. Vegetable-tanned calf develops an even more pronounced patina, improving aesthetically over the months. Milanostraps provides an 18-month guarantee on all straps; for servicing and maintenance, contact the Casati Milano atelier.