The in-house testing lab at the Morgan Hill, California, headquarters of Specialized Bicycle Components is a gleaming example of engineering efficiency: a spacious, well-lit shop where brutish machines rip and wrench bicycle frames and parts to—and past—their limits.

On this particular morning, a special frame sits on the frontal-impact rig. The Venge is an intimidating broadsword of a bike, with a menacing coat of matte-black paint bisected on the down tube by a murderous red slash. A bright white decal spells "McLaren" on the top tube, the logo of Britain’s storied supercar maker and F1 racing team, and Specialized’s longtime technology partner.

The pedal-fatigue test is long and numbingly dull. Test engineers fix the fork to a rigid point on the test jig, and the rear dropouts to an extension that simulates how a frame pivots over the rear tire’s contact patch. The final piece is a dummy drivetrain—including a cassette, chain, and overbuilt crankarms (both oriented at an angle to sustain maximum power transfer). Over the next 14 hours, the test machine alternately slams each crankarm with an excess of 1,200 N of force for 100,000 cycles—essentially a 120-rpm sprint for 14 hours straight. The test is meant to simulate cumulative pedal forces from years of riding.

Most of the time, frames get pummeled on the machine for the duration of the test cycle, then move on to the next phase of assessment. But this time, when the test finishes, there’s a problem: The frame is cracked.

For a McLaren, the failure is doubly damning. Specialized doesn’t have a separate set of fatigue benchmarks for the McLaren series, but these frames should be the best of the best of what Specialized makes. Launched in 2011, the McLaren series Venge features a carbon fiber construction that McLaren engineers ran through proprietary software designed to tune the entire frame to the absolute limit of technology and materials. Manufactured in a limited edition of 450, the complete bikes sold for $18,000.

Yet Santiago Morales, the company’s engineering manager for testing, seems unruffled by this bike’s failure. He inspects the breakage, logs the number of cycles and the location and size of the cracks, then calmly unbolts the frame and hangs it on the wall. Morales is a naturally deliberate man. His studied indifference might be because he breaks frames every day, and there is no novelty to it anymore. But in this case, Morales acts unsurprised because he is unsurprised. He expected the frame to fail at some point; the only questions were where, when, and by how much. That’s because the McLaren on the bench isn’t a McLaren at all. It’s not even a Specialized.

Greg Tombragel just wanted a good race bike. Born and raised in the Cincinnati area, the 43-year-old IT leader with General Electric’s aviation division started riding in 2007 on an inexpensive aluminum Bottecchia, “when I was about 50 pounds heavier than I am now,” he says.

Though Tombragel picked up riding relatively late in life, he made up in ability what he lacked in experience. As his fitness and physique transformed, friends suggested he try racing. And as he upgraded (he is now a category 2), so did his bikes. In 2010, he bought a BMC Racemaster SLX01, a light, stiff model made from carbon and aluminum. When the seatpost seized in the frame four years later, and the warranty claim dragged out, he began looking for a replacement bike. He tried to buy a used Specialized Venge on eBay, “but you can’t touch a one- to two-year-old frameset for less than $1,500,” he says. “I put in a few bids and lost.” Although he has a good job at GE, he didn’t want to spend the $5,500 it would have cost to purchase a new, race-ready Venge.

Ironically, it was his search for legitimate items that led him to a murky deal. “Because I’d been looking on eBay and Google, I got served up an ad in Gmail from DHgate. Sure enough, you have a frame that looks dead-on like it’s a Venge,” he recalls. “You could tell it was Chinese-direct. But I’d bought things from overseas on eBay, so I was comfortable with it.” The bike was openly advertised as a Specialized. The cost: $500, including shipping.

When the frame arrived, he took it to a shop to have the parts switched from his old BMC. But from the start, there were issues. Over the next few months, he began to notice that the dropouts weren’t totally aligned. To spin freely, the rear wheel had to be clamped slightly askew. Other oddities: Standard water bottle cage bolts didn’t fit in the frame. And after a few weeks, the screw-in cable-stop adaptor for the internally routed cables began to rust. These weren’t the only signs something was amiss. Not long after getting the bike, he had an unsettling experience on a descent. “In the chainstays and fork, there was a kind of squishy feel,” he recalls. “I just didn’t have any confidence in high-speed turns.” Similar sensations followed on other rides. Additionally, he felt unstable on the bike when sprinting. A return trip to the shop to try to fix some of the issues confirmed what Tombragel had begun to suspect. The shop owner showed a visiting Specialized rep this mysterious Venge with misaligned dropouts. After a few moments, the rep dropped the bad news: “That’s a fake.”