What a fake IW5105 actually is
Treat IW5105 as a search term first and a reference number second. IWC's hand-wound eight-day watches sit in the 5101 block (Portofino) and the 5102 block (Portugieser), so most listings using 5105 are pointing at one of those two cases with a number the seller typed loosely. Before you judge the watch, judge the listing: match the case shape, the subdial layout and the metal against the photos. If the number and the pictures disagree, stop there.
Once you know which hand-wound eight-day IWC you are looking at, sorting the fakes is straightforward. These are exhibition-back watches. There is no rotor to hide behind, the reserve runs eight days, and the mainspring is long. All three are expensive to copy well.
The movement carries the whole verdict
The real thing uses one of IWC's 59000-series hand-wound calibers, finished with striped bridges, blued screws and a signed balance cock. Replicas in this family almost always run a generic Asian hand-wound movement, dressed up with Geneva stripes and engraved plates. Under a display back, that difference shows in about ten seconds.
Three checks do most of the work:
- Power reserve. Wind it fully and set it down. A true eight-day watch keeps running past a week. Most fakes stop somewhere between 36 and 42 hours, which is the signature of a standard 6497-style movement.
- The reserve indicator. On models that show one, the hand should sweep the full arc as the spring unwinds. Cheap copies glue the needle to a printed track or tie it to the timekeeping train, so it moves when the watch ticks, not when the spring drains.
- Winding feel. A long mainspring winds for many turns with even, firm resistance. Gritty clicking, a short throw, or a crown that binds means a short-reserve movement inside.
Case, dial and crystal
The eight-day IWCs are not small watches. Most sit in the low to mid 40s in millimeters, so a listing claiming 40mm is showing you a different watch. Thickness matters too: hand-wound cases are slim for their size, and replicas often run one or two millimeters thick because the case was built around a stock movement.
On the dial, look at the applied indices and the printing. Genuine markers are polished metal with crisp, sharp edges. Fakes are usually plated with softer edges and slightly fat lettering, and the spacing between the brand text and Schaffhausen is off. Check the date aperture shape and the font on the wheel as well.
The crystal should nearly vanish. IWC uses sapphire with anti-reflective coating on both faces, so a straight-on photo shows almost no reflection. Single-coated or bare glass reads milky or blue. On the crown, the logo should be crisp and the crown should sit close to the case, not float on a long tube.
Tiers and what they cost
In replica terms, "Swiss movement" almost always means an ETA or Sellita base dropped into a Chinese-made case, not a watch assembled in Switzerland. That tier is the one worth buying here, because the case finishing and the dial printing hold up. Expect roughly $300 to $600 for a solid example of a hand-wound eight-day IWC. Anything under about $150 is a novelty with a painted movement and a reserve indicator that lies.
Before you pay
- Ask for a photo of the movement through the caseback and compare the bridge shape to official images.
- Ask for a short video of the reserve indicator moving after a full wind.
- Confirm case diameter and thickness in writing, and measure the watch when it arrives.
- Assume no water resistance, whatever the listing claims. Hand-wound display-back replicas are not sealed for swimming.
- Check the strap. Real alligator has visible scale texture and irregular edges. Embossed calf looks uniform and plasticky.
Get those answers and you will know within a minute whether the seller is offering a watch worth wearing or a photo of one.