Universal Genève Bumper Automatic 36mm 1956 Watch

Q: What is the history behind the Universal Genève Bumper Automatic (1956)?
A: This watch is an early execution of the legendary Polerouter (often signed Polarouter in earliest versions), designed by the famous Gérald Genta at age 23. Commissioned by Scandinavian Airlines (SAS) for pilots flying over the North Pole, this specific reference (20217) is historically significant as it houses the early Calibre 138SS "Bumper" movement, which predates the later Microtor models.

Q: What is a "Bumper" automatic movement?
A: Unlike modern automatics with a rotor that spins 360 degrees, the Calibre 138SS uses a hammer-style weight that swings in a partial arc, bouncing off buffer springs to wind the mainspring. You may feel a gentle, tactile "thud" or "bump" on your wrist as it winds—a charming characteristic unique to this era of watchmaking.

Q: What are the case dimensions and design features?
A: The watch features a 36mm stainless steel case, often referred to as a "Jumbo" size for the 1950s, which wears elegantly on modern wrists. It showcases Gérald Genta’s signature "twisted" or "lyre" lugs, a design element that became iconic for Universal Genève and influenced many later sports watches.

Q: Is the watch water-resistant?
A: While originally designed to withstand the rigours of polar flight, water resistance on a 1956 vintage piece cannot be guaranteed. We strongly recommend treating it as splash-proof only and avoiding swimming, showering, or heavy moisture to preserve the dial and movement.

Q: How do I set the time on this model?
A: This is a time-only watch, which maintains the perfect symmetry of the champagne dial. Simply pull the crown out gently to the setting position, rotate the gold-tone hands to the desired time, and push the crown back in. There is no date complication to set.

Q: What type of crystal does it use?
A: It features a domed acrylic (plexiglass) crystal. This material is historically correct for the 1950s and adds a warm vintage character to the dial. While acrylic can scratch, it can also be easily polished by a watchmaker to remove light marks.

Q: What is the lug width if I want to change the strap?
A: This model typically features a 19mm lug width. It comes fitted with a black leather strap, but if you wish to swap it, be sure to source a strap specifically in 19mm, as the more common 18mm or 20mm sizes will not fit the lugs correctly.

Q: Does the dial have luminous material?
A: Watches from this period often used Radium or early Tritium for hour markers. Over 70 years, this material loses its glow and develops a patina. We recommend leaving the dial untouched to preserve its original collector value and vintage aesthetic.

Q: What maintenance does the Bumper movement require?
A: The Calibre 138SS is robust, but like all vintage mechanical movements, it benefits from regular servicing every 3–5 years. If you hear unusual noises or the watch runs significantly fast or slow, have it inspected by a professional watchmaker familiar with vintage bumper automatics.

Q: Is the "Champagne" dial original?
A: The dial has a warm, golden "Champagne" tone. In vintage collecting, this can be an original colour variant or the result of a beautiful, even patina forming on a silver dial over decades. This unique aging process makes each vintage piece truly one-of-a-kind.