When you evaluate a fake IW371787, the core advice is to compare the replica against the authentic IWC Portugieser Chronograph reference on three points: case proportions, dial layout, and movement type. A high-quality replica will match the 41mm case width within 0.5mm, the 20mm lug width, and the subdial positions at 12 and 6 o'clock. Lower-grade fakes often get the subdial spacing wrong, use a cheap quartz movement, or paint the dial instead of applying indices. Start by checking those fundamentals before you consider any other feature.

What to look for in a replica IW371787

  • Case shape and finish: The genuine IW371787 has a polished bezel and brushed case sides. A good replica will show a clear separation between those finishes. Look for sharp lug edges and a smooth crown.
  • Dial details: The subdials should sit at 12 and 6. The date window, if present, must align with the 3 o'clock position. Indices should be applied metal, not printed. The IWC logo must be crisp and with correct spacing.
  • Hands: Leaf-shaped hands with a polished finish. The chronograph seconds hand should reach the minute track.
  • Movement: Many replicas use a Chinese clone of the Valjoux 7750 or a Seagull ST19. A high-quality fake will have a smooth sweep on the seconds hand and a working chronograph with a crisp reset.
  • Crystal: Sapphire with anti-reflective coating on both sides. A cheap fake uses mineral glass that reflects light.

Parameter bands that matter

These ranges separate a good replica from a poor one. Use them as a checklist.

  • Case diameter: 40.5mm to 41.5mm. The genuine is 41mm.
  • Case thickness: 12.5mm to 13.5mm. Too thin means a quartz movement.
  • Lug width: 20mm. Straps must fit without gaps.
  • Weight: 80g to 110g on a leather strap, depending on movement. A very light watch signals cheap materials.
  • Water resistance: The real watch is rated to 30m. Most replicas are not safe for swimming. Do not expect more than splash resistance.

Common pitfalls

  • Subdial spacing that is too wide or too narrow. This is the most common flaw.
  • Date window with a magnifier or wrong font. The IW371787 has no cyclops in most versions.
  • Printed dial markers instead of applied metal.
  • Chronograph pushers that stick or feel mushy.
  • Caseback engraving with wrong reference number or poor depth.
  • Movement that ticks once per second, which means quartz, not automatic.

FAQ

Is a fake IW371787 worth buying?

It depends on your goal. If you want the look of a Portugieser Chronograph without the authentic price, a high-grade replica can work. But you accept lower reliability and no warranty. Buy from a seller who shows real photos and offers a return window.

How can I tell a good fake from a bad one?

Ask for close-up photos of the dial, caseback, and movement. Compare subdial positions and logo spacing against official IWC images. A good replica will have crisp edges and correct proportions. A bad one will look flat and use printed details.

What movement should a quality replica use?

Look for an automatic chronograph movement, such as a clone of the Valjoux 7750 or a Seagull ST19. Avoid quartz. The seconds hand should have a smooth sweep, and the chronograph should start, stop, and reset with a firm click.

Can I wear a fake IW371787 every day?

You can, but expect wear on the plating and gaskets. Keep it away from water and extreme heat. A replica is not built to the same tolerances as the genuine watch, so service options are limited.