A replica IW371740 is a copy of the IWC Portugieser Chronograph reference IW371740, a 40.9 mm stainless steel chronograph with a two register dial and the caliber 79350. The strongest replicas get the case diameter, the subdial positions and the thin feuille hands right, and the weakest ones fail on dial print, crown shape and movement finishing. Buy on those three points, not on the photo lighting.
What defines the IW371740 reference?
The reference sits inside the IWC Portugieser Chronograph family, which pairs a slim steel case with a railroad style minute track and applied numerals. IWC lists the line at 40.9 mm across and about 12.3 mm thick, with sapphire crystal, 30 m water resistance and the 79350 automatic chronograph movement. Because the reference number encodes a specific dial and strap combination, confirm the exact dial color and strap option on IWC's own model page before you compare a replica side by side.
What movement should a replica IW371740 use?
The genuine caliber 79350 is a heavily reworked Valjoux 7750, so the honest replica path is a 7750 based clone with the same 12 6 subdial layout. That shared architecture is why good replicas get subdial spacing right, unlike watches built on unrelated quartz or modular movements.
- Asian 7750 automatic: the standard choice, 28,800 vph, roughly 40 to 44 hours of power reserve, correct running seconds at 6 and chronograph minutes at 12.
- Swiss or Swiss clone 7750: smoother pusher feel and quieter rotor, usually reserved for the top tier.
- Quartz: thinner case and a ticking seconds hand at 6, which is wrong for a mechanical chronograph.
Expect rotor noise and a slight wobble on any 7750 based watch, including the genuine article. Confirm that the chronograph starts, stops and resets cleanly and that the pushers feel crisp rather than mushy.
How close are the case dimensions?
A serious replica should measure within a few tenths of a millimeter of 40.9 mm and stay near 12 to 13 mm thick. Ask for caliper photos, because listings often reuse the same numbers regardless of what ships.
Also check lug width, which should be 20 mm, and the strap taper. An oversized crown, a domed caseback that sits too proud, or polished surfaces that are too mirror bright are common tells.
Which details give a replica away?
- Dial print: the brand signature and the model line above the lower subdial should be thin, sharp and evenly spaced.
- Applied numerals: genuine markers are polished and faceted, and cheap replicas use flat stamped pieces.
- Hands: feuille hands must be slender with a clean center crease and no rough edges.
- Subdial rings: the snailing should be fine and concentric, not a printed texture.
- Crown and pushers: correct proportions and a signed crown with crisp engraving.
- Caseback engraving: shallow laser etching instead of deep, clean stamping.
How much should a replica IW371740 cost?
Entry level pieces with a basic 7750 and thin plating typically land in the low hundreds of dollars, and they show it in the dial. Mid tier versions with a corrected dial and better case finishing sit in the middle of the market and represent the usual sweet spot. Top tier builds with a Swiss clone movement and hand finished case parts cost considerably more, and at that point the gap to a used genuine watch deserves a hard look.
What should you check in QC photos?
- Dial straightness under direct light, with the subdials centered on the vertical axis.
- Case thickness measured with calipers, not quoted from the listing.
- Chronograph reset returning both hands exactly to zero.
- Crown threading and pusher travel.
- Strap stitching, buckle engraving and spring bar fit.
Reject any set of photos that hides the dial print or the caseback. A seller who will not shoot those two angles is not a seller worth wiring money to.
Is a replica IW371740 worth buying?
If you want the Portugieser look on a real mechanical chronograph movement without genuine pricing, a well built replica is a reasonable novelty purchase. If you want long term servicing, resale value and water resistance you can trust, the genuine reference remains the only answer.