Buy the replica that copies the 41 mm Portugieser Chronograph case and the 69355 subdial layout, and walk away from anything built on a stock 7750 with the counters in the wrong place. On this reference the running seconds sit at 6 and the 30 minute counter sits at 12, both set into the dial with a fine concentric snail pattern, and there is no date window on the face. If a seller's photos show a date at 3, subdials that crowd the center, or a case that measures 42 mm or wider, the watch is the wrong base and no amount of dial printing will rescue it. Ask for the movement name first, then the case measurements, then macro photos of the dial. Price comes last.
Why this dial is hard to copy
The Portugieser Chronograph leaves a lot of open dial, and open dials show mistakes. The two subdials, the leaf hands, the applied markers and the thin minute track all sit on empty ground, so a crooked logo or a hand with the wrong curve is visible from across a table. Most weak replicas fail at this stage, before anyone opens the caseback.
Fake IW371717 Question: How to Check an IWC Portugieser
What to look for
Case and crystal
Run calipers across the case at 3 and 9. You want 41.0 mm with a small tolerance either way, and a flank that flows into the lugs without a step. The bezel is thin and polished, the case band brushed, and the line between them should be crisp. The genuine crystal is sapphire with antireflective coating on both faces, which is why the dial reads deep black at some angles. A replica coated on the inside only gives a flat, milky look under store lights. Check the crown: signed, sharp fluting, and seated so it does not catch a sleeve.
Fake IW371717 Synonym: What You Need to Know
Dial and hands
Subdials at 12 and 6, with a clear gap in the middle for the two lines of text. The small seconds hand at 6 should sweep, not jump in half second steps. Look for concentric snailing inside each subdial and a matte finish between them. Applied markers should throw a hard highlight when you tilt the watch, not sit flat like decals. Leaf hands taper to a point without a burr, and on blue dials the hands should read dark, not bright chrome.
Fake IW371717 Compared to Genuine IWC: Side-by-Side Review
Movement
Get the movement name in writing. The genuine watch uses the in-house calibre 69355, a column wheel chronograph with a 46 hour reserve, so a good replica either clones that layout or re-gears a 7750 to move the counters to the right positions. Re-geared 7750 builds work, but the pusher feel is heavier and the subdial hands can drift off zero. A column wheel clone starts and stops with a light click, and the chrono seconds snaps back without a wobble. Ask for a short video of start, stop and reset.
Caseback and finishing
Sapphire display back, an engraved rotor, straight brushing on the bridges. Rotor engraving should be cut, not printed. Look at the caseback thread and the gasket seat, because that is where water resistance actually lives.
Sizes and specs to check
- Case diameter: 40.8 to 41.2 mm on calipers. The genuine is 41.0 mm. Anything at 42 mm or above is a different case.
- Case thickness: about 13.0 mm on the genuine. A build that measures over 14 mm is usually a 7750 sitting too tall in the case.
- Lug width: 20 mm, with a curve that follows the case flank.
- Subdials: 12 and 6, with enough space between them for the dial text. No date aperture anywhere.
- Beat rate: 28,800 vph (4 Hz). A 21,600 vph reading on the timegrapher points to a lower grade movement.
- Power reserve: 44 to 48 hours. Under 40 hours suggests a tired or budget base.
- Weight: 80 to 95 g for the head on a leather strap. A very light head points to a thin plated case.
Common pitfalls
- Subdial spacing that comes from a stock 7750 layout, with the 12 o'clock counter pulled toward the center.
- A date window at 3 that does not belong on this reference.
- Blue dials that shift purple or teal in daylight, or carry a sunburst that is stronger than the original.
- Mushy pushers with rough threads, or a reset that kicks the chrono hand past zero.
- Photos lifted from a genuine owner or from an older listing. Request a timestamped shot with the crown pulled.
- Water resistance claims above 30 m on a case that was never pressure tested.
A five minute check before you pay
- Ask for macro shots of the dial, the subdials and the caseback engraving in daylight.
- Request a timegrapher photo showing rate, amplitude and beat error.
- Ask for a video of the chronograph start, stop and reset.
- Confirm the movement name and the factory in writing, not in a chat sticker.
- Compare the seller's dial photo against a catalog image of the same dial color and reference.
FAQ
Is IW371717 a real reference?
Yes. The number sits in the IW3717 block used for the 41 mm Portugieser Chronograph generation that replaced the older 3714 and moved to the in-house calibre 69355. Ask which reference the replica was patterned from, since dial colors and strap options differ across the block. A dial that does not match its stated reference is a sign of a catalog build rather than a copy of one specific watch.
Column wheel clone or 7750 build?
Column wheel clone if the seller can name the factory and show a pusher video. The 7750 build costs less and is easier to service, but the gearing is a compromise and the case tends to sit taller. Daily wear favors the column wheel version. Occasional wear favors the 7750, which is the lower risk purchase.
Can I swim with a replica?
No. Treat any replica as splash resistant at best, even when the caseback is engraved with a depth rating. Gaskets on replicas are not tested, and a service to reseal the case costs more than the risk is worth.
Will a watchmaker spot it?
On the wrist, rarely. With the caseback open, yes. Movement finishing, the regulation system and the engraving depth give it away in seconds, so plan on a watchmaker seeing the truth if you ever take it in for service.
What matters most at the price?
Case geometry and dial layout, in that order. A correct 41 mm case with properly placed subdials looks right from a meter away. A perfect movement inside a wrong case still looks wrong, and nobody sees the movement while you wear it.