Strap for Bellflower Tonneau Yellow Gold / Silver / Bracelet

The lug width of the Tissot Bellflower T73.3.323.31 is 18mm. This measurement represents the internal distance between the two lugs of the case. Any strap intended for this model must respect this dimension precisely: a 16mm or 20mm strap will not fit correctly. The correct measurement is performed by inserting a digital calliper into the space between the two lugs at the point where they emerge from the case.

The ideal strap depends on intended use and aesthetic preference. For a dress watch of this calibre, an alligator leather strap in cognac or dark brown represents the classical choice: the characteristic grain of alligator leather combines elegance with durability. For those desiring natural patina over time, Italian vegetable-tanned calf is excellent. For versatility and ease of replacement, a cotton or silk NATO offers practicality whilst maintaining refinement. Structured rubber performs excellently for warm seasons or less formal contexts without sacrificing elegance.

Strap replacement on the T73.3.323.31 is performed via the removable spring bars present at the case lugs. With a dedicated tool (spring bar tool), one compresses the bar on one side, extracts it from its seat, and repeats on the opposite end. Once the case is free, the new strap is inserted by threading the spring bars through the opposite lugs, ensuring the bar is fully seated and locked in position. If the strap features an integrated leather keeper, verify that it sits comfortably with natural folding.

Technical compatibility is guaranteed for all 18mm straps equipped with standard spring bars (1.5–1.6mm diameter). Aesthetic compatibility, however, depends on leather quality, texture, and finishing. Low-quality leather straps may delaminate or deteriorate rapidly, compromising the entire watch experience. It is advisable to choose specialised manufacturers who understand the specific proportions of an 18mm dress watch and offer certified leathers (genuine alligator, vegetable-tanned calf, shell cordovan).

The lifespan of a leather strap depends on tanning quality and daily wear. A genuine alligator strap in good condition may last 5–8 years with regular wear. Vegetable-tanned calf typically lasts 3–5 years depending on humidity and sunlight exposure. Deterioration usually begins at the fold (where the keeper meets the main strap) and along stitching. To extend strap life, minimise exposure to moisture, handle gently at the lug attachment, and avoid keeping it folded in excessive heat. Preventive replacement every 4–6 years ensures a smooth transition without excessive case wear.