Breguet
Classique 5140BB/29/9W6— lug 20mm

The Breguet Classique 5140BB/29/9W6 is fitted with a 20mm lug width. This is the standard size adopted by Breguet across the entire Classique family with 40mm cases. To verify it on your own watch, measure with a digital caliper the internal distance between the two lugs in the area where the strap attaches.

For a case in 18-carat yellow gold like the 5140BB/29/9W6, the most appropriate strap is smooth alligator belly cut in midnight blue, burgundy, or cognac tones, paired with a yellow gold bar buckle. Smooth alligator does not introduce texture that competes with the dial's guilloché and ensures a wrist-friendly fit with contained thickness, compatible with the shallow profile of the Classique case.

The strap is removed using a dedicated spring bar tool inserted into the slot between the lug and the strap attachment pin. On a yellow gold case, it is advisable to use a tool with a plastic or Teflon-coated tip to prevent micro-scratches on the lugs. For those without experience, it is best to entrust the operation to a watchmaker or the Casati Milano atelier, where the change is performed with tools dedicated to precious metals.

Yes. All straps with standard 20mm attachment are technically compatible with the Breguet Classique 5140BB/29/9W6. Quality aftermarket production—such as the artisanal offering from Milano Straps—provides leather and finishes equivalent to or exceeding those of manufacture originals, with the ability to customize color, texture, stitching, and buckle type. It is important to choose straps with a standard 1.5mm spring bar diameter to ensure proper attachment.

The lifespan of a leather strap depends on the leather quality, frequency of wear, and exposure to sweat and humidity. A quality alligator, worn in rotation with other straps and kept away from water and creams, maintains structural and aesthetic integrity for 3-5 years. Calf box leather develops characteristic patina within the first 12-18 months, but may show wear at the buckle and adjustment holes sooner. Straps produced by Casati Milano are covered by an 18-month warranty against manufacturing defects.