Strap for Pilot's Watch Chrono-Automatic Edition Top Gun

The lug width (lug size) of the IWC Pilot IW3789-01 is 21 millimetres. This measurement refers to the distance between the lateral pins that hold the strap. It is essential to verify this specification before purchasing an aftermarket strap: 21mm is the only compatible size for this model. The measurement must be taken from pin to pin, not including the width of the case itself.

The most suitable strap depends on intended use. For formal contexts and professional pilots, an Italian-tanned alligator with fine graining is the optimal choice: it resists thermal variations at altitude and maintains elasticity in humid climates. For alternating between daily wear and outdoor activities, vegetable-tanned calf leather offers initial softness and develops a natural patina over time. A vulcanised black rubber strap is ideal for those who prioritise resistance to moisture and chlorine. All three materials are available in 21mm size compatible with the model.

Strap replacement is carried out by removing the lateral pins with a dedicated tool (spring bar tool). Position the pin from the lower side towards the outer part of the lug, then remove it gently. Remove the old strap and insert the new one by aligning it with the lug holes. Reinsert the pin, ensuring it is fully locked in position. It is advisable to have a clean surface and adequate lighting to avoid losing the tiny pin. If you are not confident, a professional watchmaker can perform the operation in a few minutes.

All straps manufactured for the 21mm lug width are compatible with the IWC Pilot IW3789-01. This includes alligator, calf, crocodile, rubber, and 21mm NATO straps. MilanoStraps offers a dedicated collection of 21mm straps customisable in leather, colour, thickness and thread colour. It is important to purchase exclusively from suppliers who clearly specify the lug size (21mm) to avoid ordering errors. Professional straps in alligator or vegetable-tanned calf have an average lifespan of 3–5 years with constant use.

Durability depends on the material and conditions of use. An alligator strap tanned vegetally lasts on average 3–5 years with daily use; alligator is more durable than calf due to the structure of the hide. Vegetable-tanned calf leather has a similar lifespan but acquires progressive patina and darkening, enhancing the aesthetic over time. A vulcanised rubber strap lasts 5–7 years or longer, as it is not subject to drying out. Regular maintenance (conditioning with natural wax every 6–8 months) extends the lifespan of any leather strap. Natural wear of stitching is a foreseeable phenomenon: MilanoStraps offers a guaranteed re-stitching service for 18 months.