Quick Answer
A fake Big Pilot IW5105 is a replica of the IWC Big Pilot's Watch. It copies the wide pilot case, the oversized conical crown, the black dial with large luminous hands, and the power reserve display. It does not copy the movement architecture, the finishing, or the manufacturing tolerances. Most replicas run a generic Asian automatic or a hand wound 6497 style movement fitted with a decorative power reserve hand. Judge one by the case profile, the crown shape, the dial print, the date wheel, and the movement visible through the case back.
What You Need Before You Inspect
- Calipers or a ruler with millimeter marks
- A 10x loupe
- Bright, angled light (a desk lamp works better than overhead light)
- A reference photo of a genuine IW5105 from a dealer listing, side by side
- A soft cloth and a spring bar tool if you plan to check the strap
Traits the Genuine IW5105 Carries
The IW5105 sits inside the Big Pilot's Watch family, so it inherits the model line's hallmarks. Expect a broad stainless steel case in the 46 mm range, a case thickness built around a large automatic movement, a domed sapphire crystal with anti reflective coating on both faces, and a screw down case back. The crown is the give away feature on this line: a large conical onion shape with deep fluting, easy to grip with gloves, and it sits proud of the case without overhang. Dial layout is matte black with applied numerals, a power reserve arc or subdial, and a date window with a white disc and black font. Lume is applied thick enough to see a slight dome under a loupe.
How to Inspect a Replica IW5105 Step by Step
- Measure the case across the widest point, excluding the crown, and compare the number to the published spec for the reference. A replica that reads 1.5 mm wide of spec is common.
- Measure case thickness from the back of the lugs to the top of the crystal. Replica cases tend to run thicker because the movement sits higher.
- Look at the crown from the side. Genuine crowns are conical with sharp flutes. Replica crowns are often flatter, rounder, and slightly smaller.
- Check the crown action. Winding should feel tight and mechanical with no grit. A grinding or loose crown points to a cheap stem and tube.
- Study the dial print under the loupe. Look at stroke weight, spacing, and the shape of the numerals. Replica print is usually heavier and slightly fuzzy at the edges.
- Inspect the date window. Check the position, the font on the numbers, and the alignment of the disc inside the cutout. Off center dates are the most common flaw.
- Watch the power reserve hand. On a genuine watch it moves in small increments tied to the mainspring. On many replicas it is driven by a separate gear train or simply glued to a fixed position.
- Examine the hands at an angle. Genuine hands are diamond polished with crisp edges. Replica hands show tool marks, rounded edges, and uneven lume fill.
- Turn the watch over. Read the case back engraving and serial number. Replica engraving is shallower, with uneven letter spacing and a serial that repeats across many units.
- Look through the display back if the replica has one. Compare the rotor engraving, the bridge shape, and the jewel count to a photo of the genuine movement.
- Test the strap and buckle separately. Genuine leather has a consistent grain and the buckle tang is rounded and polished. Replica straps are thinner and the buckle shows sharp edges.
- Time the watch over 24 hours. Note the rate and the position error. Anything outside plus or minus 15 seconds a day signals a low grade movement.
Movements You Will Find Inside Replicas
- Asian 6497 or 6498 hand wound, often with a decorative plate that fakes an automatic rotor
- Miyota 9015 based automatics, thin and reliable but with a small power reserve
- Cloned Swiss style automatics with cosmetic engraving on the rotor
- Quartz movements hidden behind solid case backs on the cheapest tiers
Marketplace Reality Check
No replica carries an IWC serial number that matches a real watch, and a counterfeit bearing a protected trademark is an illegal copy in most countries. That matters at resale, at customs, and at any service center. A watchmaker will work on a replica for a fee, but parts are not interchangeable with the genuine calibre, so a failed movement usually becomes a full replacement. If a seller claims the watch is genuine, ask for the warranty card, the box, and a service history. No paperwork plus a low price equals a replica.
Questions Buyers Ask
Is a fake IW5105 the same size as the real one?
Close, but rarely exact. Most replicas land within 1 to 2 mm of the published case dimensions, and thickness is where the difference shows most.
Can a jeweler tell it is a replica?
Yes. A watchmaker with a loupe and calipers will spot the crown profile, the dial print, and the movement within a minute of handling it.
Does the power reserve actually work on a replica?
On most, no. The hand moves because it is geared to the running train, not because it reads mainspring tension.
Should I buy one with a display case back?
Only if you accept that the movement will look different from the genuine calibre. A solid case back hides more of the tells.