Buy the movement first. A fake IW371470 is worth considering only when it runs an automatic 7750-family chronograph movement, because the genuine Portugieser Chronograph ref. 3714 is built on that architecture and its character follows from it: crisp pusher action, subdials with chronograph minutes at 12 and running seconds at 6, and a case that sits around 12.3 mm thick. If the seller cannot confirm a 7750 clone, stop studying dial photos and move on. Everything below assumes that first box is ticked.
Why this reference is friendlier to replicate than most
The ref. 3714 has a solid caseback and a dial that hides its complexity in plain sight. There is no exhibition back showing finishing, no skeleton work and no exotic escapement. A well-built replica therefore has fewer places to embarrass itself than a copy of a Lange or a Royal Oak. The visible tells narrow to four areas: how the movement behaves, how thick the case is, how the dial and hands are finished, and what strap comes with it.
What to check, in order
1. The movement
Ask for a photo of the movement with the caseback off, plus a timegrapher readout. A 7750 clone should show 28,800 vph, amplitude in the 270 to 310 degree range when fully wound, and beat error under 0.5 ms. Winding should feel smooth and the rotor should swing with a light shake. A quartz build is simple to spot: the small seconds at 6 ticks once per second instead of sweeping, and the pushers feel like buttons on a calculator rather than a mechanical linkage.
Beware of decorated movements where the chronograph functions are simulated. On those, the central seconds hand often snaps back without the small hesitation of a cam reset, and the minute counter at 12 does not advance in step with the seconds hand.
2. Case size and thickness
The genuine case measures 40.9 mm across and about 12.3 mm thick, with 20 mm lugs. A 7750-based replica can land close to those figures. Cheaper builds often sit at 13.5 mm or more because the maker used a spacer over a thin movement or a case designed for something else. Thickness is the tell you can catch in a wrist shot, so request a side profile photo next to calipers or a ruler.
3. Dial and hands
Check subdial spacing first: the two subdials should sit near the centre, chronograph minutes at 12 and running seconds at 6, with the date window at 3. On the genuine dial the IWC logo is an applied metal piece, the Schaffhausen text is printed with tight kerning, and the leaf hands show a centre crease. Replica faults appear as a flat printed logo, subdials spread too wide, a date font that is too broad, and hands that look stamped rather than milled.
4. Crystal, caseback and strap
The sapphire should be slightly domed with anti-reflective coating on both faces, which leaves almost no reflection at an angle. Single-sided coating gives a blue or purple sheen, a common giveaway in daylight. The solid caseback should carry deep, crisp engraving with the reference and serial numbers. The strap should be alligator or a convincing embossed calf with a signed pin buckle. Low-grade replicas ship with stiff, glossy leather that creases badly within weeks.
Parameter bands worth asking about
- Case diameter: 40.8 to 41.1 mm
- Case thickness: 12.2 to 12.6 mm
- Lug width: 20 mm
- Movement: automatic 7750 family, 28,800 vph, 25 or more jewels, 40 hours or more of power reserve
- Crystal: domed sapphire, anti-reflective on both sides
- Water resistance: 3 bar nominal, splash only in practice
- Dial: applied logo, subdials at 12 and 6, date at 3, rail-track minute ring
- Weight: a steel case should feel dense in the hand; a hollow or light case points to a quartz build
Pitfalls that catch first-time buyers
- Buying from photos alone. Studio lighting hides AR tint, dial print quality and case finishing. Ask for a video with the chronograph running.
- Trusting labels such as 1:1 or mirror quality. These are marketing terms, not specifications. Ask which movement is inside, what the measured thickness is, and whether both chronograph functions work.
- Ignoring the date wheel. The date sits at 3 with a specific font and a clean cut window. Misaligned or oversized date fonts are one of the easiest tells.
- Skipping the timegrapher. A seller who cannot supply rate, amplitude and beat error numbers has not looked at the watch.
- Assuming water resistance. A replica is a splash-resistant watch at best. Do not swim with it and do not test it in a pool.
- Forgetting service. A 7750 clone can be regulated and serviced by any competent watchmaker, which matters more than a fancy presentation box.
Know what you are buying. A replica holds no resale value, is not an investment, and importing one can carry customs risk depending on where you live.
FAQ
Is the movement in a fake IW371470 the same as the genuine?
Same architecture, different execution. IWC uses calibre 79320, a Valjoux 7750 base that it regulates and finishes in-house. A replica uses a 7750 clone, mostly sourced from Chinese factories. The layout, beat rate and subdial functions match; the finishing, regulation and long-term reliability do not.
Can I tell a replica by case thickness alone?
Often, yes. The genuine is about 12.3 mm thick. If a listing shows a slab-sided case closer to 13.5 mm, it is either a quartz build or a mismatched case. Ask for calipers.
Do the subdials actually work on a good replica?
On a 7750-based build, yes. The chronograph minutes at 12 and the running seconds at 6 both function. On a quartz build the 12 o'clock subdial is often frozen or faked, which is the fastest way to rule a watch out.
Should I pay more for a Swiss made replica?
Ask what is actually Swiss. In most cases the answer is a Swiss movement blank assembled elsewhere. Pay for measurable things: a confirmed 7750 clone, correct thickness, clean dial print, and a seller who supplies movement photos and timegrapher data.
How long will a replica IW371470 last?
A 7750 clone that is regulated and kept clean can run for years. The weak points are the pusher seals, the crown gasket and the strap. Budget for a service and a replacement strap rather than treating the watch as disposable.