A fake IW371766 is a replica of the IWC Portugieser Chronograph in the 3717 reference family, a watch built around a slim steel case in the 40 to 41 mm range, two chronograph subdials, and a dress-watch profile. It is one of the most copied IWC references because the design is simple to machine and easy to sell. Replica versions range from low-cost quartz builds to Swiss-movement copies that mirror the case proportions and dial layout closely.
What the IW371766 Reference Is
The original sits in the Portugieser line, IWC's oldest family and the one most associated with clean Arabic numerals, leaf-shaped hands, and railroad-style minute tracks. The chronograph version adds two subdials, a small seconds at six o'clock on most executions, and a tachymeter or plain outer ring depending on the variant. IWC has produced this silhouette in stainless steel, red gold, and white gold, plus limited dial colors and special editions.
That range matters for buyers of a fake IW371766. The more factory dial and case combinations exist, the harder it is to call out a replica on color alone, and the easier it is for a seller to claim a variant "always looked like that."
Why This Reference Gets Copied
- Flat sapphire crystal and a simple stepped bezel, both easy to reproduce.
- Two-subdial layout that hides most of the complexity behind the dial.
- Leather strap and pin or deployant clasp, so no bracelet links have to be matched.
- Strong brand recognition, which keeps demand steady on the secondhand and gray markets.
- Dial printing that is mostly text and thin indices, a job modern replica factories handle well.
What Separates a Good Fake IW371766 From a Cheap One
Case and finishing
On a better replica, the case sides show brushed surfaces with polished chamfers along the lugs, and the transition between the two is crisp. On a cheap build, the brushing runs over the edges and the lugs feel soft or rounded. Case thickness is another tell. A thin quartz copy often sits closer to the wrist than the original automatic, and the crown sits too close to the case band.
Dial and hands
Index alignment is the fastest check. Look at the gap between each applied marker and the minute track, and see whether the gaps match on all twelve. Subdial rings should be concentric and evenly spaced, and the hands should reach the track without overshooting it. Applied numerals on a low-end copy are often glued slightly off center or sit at different heights.
Strap and clasp
Replica alligator is usually embossed calf leather with a printed scale pattern. Real alligator has irregular scales with visible pores and a grain that changes across the strap. Stitching should be even and single-needle consistent, and the clasp engraving should be sharp rather than shallow and fuzzy.
Movement: The Real Divide in a Replica IW371766
Three movement classes show up in replica IW371766 listings. Quartz movements are the cheapest and give a ticking seconds hand, which is immediately wrong on a mechanical chronograph. Asian automatic chronograph movements based on the Valjoux 7750 architecture are the middle tier and drive the subdials correctly. Swiss ETA 7750-based movements sit at the top, with smoother pusher feel and better timekeeping, though they add cost and still do not match the finishing of a genuine in-house caliber.
Pusher feel is a useful field test. A mechanical chronograph should start, stop, and reset with a firm, short travel. Mushy or long pusher throw usually points to a cheap module stacked on a basic automatic.
How to Inspect a Fake IW371766 Before Buying
- Ask for a straight-on dial photo in daylight, not a filtered or angled shot.
- Request a movement photo with the caseback removed, or a short video of the chronograph running and resetting.
- Check the caseback engraving depth and the reference and serial font against known photos of the reference.
- Measure the case diameter and thickness with calipers if you can handle the watch in person.
- Check crown operation and winding feel, plus date change if the variant has a date.
- Confirm the strap material in writing, since embossed calf is often described as alligator.
Common Mistakes Buyers Make
- Judging quality from a single heavily edited product photo.
- Assuming a higher price always means a Swiss movement.
- Ignoring case thickness and lug profile, which are the hardest parts to copy well.
- Overlooking the strap, which is often the weakest component on an otherwise solid replica.
- Treating any replica as an investment. A fake IW371766 has resale value only within the replica market.
Legal and Practical Notes
The Portugieser name, the IWC logo, and the reference numbering are protected trademarks. Selling a replica as a genuine IWC is fraud, and counterfeit trademarked goods can be seized at the U.S. border. A fake IW371766 should never be represented as an authentic watch, and it should not be taken to an authorized service center for work, since many will decline to service or return it.
If the goal is to compare the look of the reference before committing to a genuine purchase, a replica can serve that purpose. If the goal is ownership of the real watch, buy from a seller with documented service history and an inspection window, and treat any unusually low price on a steel Portugieser Chronograph as a warning sign.