Janet Kowal had a personal connection to the Register’s Annual Great Bicycle Ride Across Iowa (RAGBRAI). Even though she’s now living outside Chicago, working for the Village of Burr Ridge town hall, Kowal has Iowa in her blood. The 2013 route would take her through her hometown of Des Moines and skirt the University of Iowa, where she graduated in 1987. Kowal bought a new-to-her 2007 Giant OCR C1 road bike for the event and, to be cautious, took it to her local bike shop for a full-service tune-up.

Not long into the ride, however, Kowal’s bike shattered beneath her. For no apparent reason—she’d neither hit an obstacle nor encountered a pothole—the front fork snapped in half as if it had exploded from within. Kowal was sent crashing into the pavement, helmet first. She fractured her spine and clavicle, suffered a concussion, and tore ligaments in her left thumb.

After missing weeks of work and racking up medical bills for surgeries on her hand, Kowal sued in 2013. She went after the shop that sold her the bike, the one that serviced it, and then Giant itself. The lawsuit, filed in Cook County, Illinois, claims that a manufacturing defect in the fork’s carbon fiber caused it to fail.

Taiwan-based Giant quickly tried to bow out. The company argued in court filings that there’s an entirely independent Giant in the United States in charge of distribution to authorized retailers. While Giant of Taiwan made the bike, it can’t be held liable, the company claimed, because it doesn’t do business in Illinois, and the U.S.-based Giant shares no negligence either because it didn’t make the bike.

The company’s argument wasn’t new. It has been made in hundreds of similar lawsuits involving foreign-made bikes. In many of them, the logic has been enough to sway judges to throw out lawsuits or convince bike owners to settle. But the judge in Kowal’s case said the lawsuit could go forward against both Giant of Taiwan and its U.S.-based cousin. Giant appealed; in September, the Illinois Appellate Court agreed to let the lawsuit continue—the first time an appellate court has weighed in on such a case.

“This is an area of law that has been in flux in recent years,” says Ken Hoffman, Kowal’s Chicago-based attorney. “The bike manufacturers are like nesting dolls. They set up layers and layers of companies to try to protect themselves, but finally they are being held liable.”

There’s already a cottage industry of people who specialize in lawsuits resulting from bike accidents, including a growing cadre of attorneys and forensic experts who specialize in carbon fiber. Now that use of the material, once reserved for high-end bikes, has become widespread in the bike industry, reports of accidents and mysterious failures are on the rise. Kowal’s case signals that bike manufacturers—even overseas brands—may now be held accountable. The result could be a dramatic spike in the number of lawsuits brought against makers of carbon-fiber bike parts.

“There’s an old saying in bike manufacturing: It can be lightweight, durable, or cheap—pick two. A lot of these carbon-fiber components are lightweight and cheap, but they are not durable.” says Luke Elrath, an engineer who once designed kids’ bikes for Trek and now works as a bicycle-accident expert for Robson Forensic in Philadelphia. Soon after joining the firm in 2012, Elrath began noticing an uptick in calls from lawyers looking for his analysis of carbon-fiber bicycle components that had failed under their clients. After researching how the carbon components in these cases were made, Elrath now believes many of the accidents occurred because of faulty design and construction.

Elrath is one of several experts in carbon-fiber bike accidents. Their names are circulated among members of Bike Law, a network of independent lawyers and firms that use a website and listserv to share stories on carbon-fiber failures. Attorney James B. Reed is a New York state representative of Bike Law and has handled two lawsuits where clients suffered catastrophic injuries when carbon-fiber components failed below them. He has heard about numerous others from people on the Bike Law listserv.

“There’s an old saying in bike manufacturing: It can be lightweight, durable, or cheap—pick two,” Luke Elrath says. “A lot of these carbon-fiber components are lightweight and cheap, but they are not durable.”

Reed and other experts in carbon fiber agree that any material can fail. Wrecks happen from faulty aluminum, steel, and even rock-hard titanium. The difference with carbon fiber is that it can be difficult to detect signs of damage that might signal imminent failure. Cracks and dents in other materials are typically easy to see, but fissures in carbon fiber often hide beneath the paint. What’s worse is that when carbon fiber fails, it fails spectacularly. While other materials might simply buckle or bend, carbon fiber can shatter into pieces, sending riders flying into the road or trail. And this kind of catastrophic destruction can happen to any part of a bike made with the material.

“I’ve seen accidents from a whole range of carbon-fiber components—handlebars, forks, seatposts, entire frames,” Reed says. “As a lawyer, the question is, ‘What’s the cause of the failure?’”

That’s a question Philip W. Coats, an attorney in San Diego, set out to answer when he represented a client whose front fork shattered. Coats obtained documents from the Chinese manufacturer (a settlement agreement forbids him from naming the company). Using a Mandarin translator, he found that the factory had no standards on how carbon fiber is produced. No rules restricted how thick it should be or how much impact it needed to absorb in a collision, Coats said.

It’s not that all carbon fiber is dangerous. When made well, carbon fiber can be tougher than steel and quite safe. But when made incorrectly, carbon-fiber components can easily break. The parts are built by layering fibrous carbon that’s bound together with resin. If the manufacturer skimps on the resin or simply applies it unevenly, gaps can form, making it susceptible to cracks. Those fissures can spread from an innocuous collision, like the impact of a bike lock or simply from landing hard coming off a curb. Over days or sometimes years, the fracture spreads until, in many cases, the material shatters. Time is often the crucial element.

Steven Sweat, a bicycle-accident attorney in Los Angeles, says he has worked on numerous carbon-fiber cases, more and more in recent years as the components age. “There are problems with manufacturing, but we’re also just testing the limits of how long carbon can last,” Sweat says.

What’s more, even if a carbon-fiber component is well made and has never suffered a routine ding or collision, accidents can occur due to poor maintenance. Unlike with other materials, if you overtighten carbon-fiber parts, they’re likely to shatter down the road. Often, owner’s manuals offer little guidance on how to maintain the material, leaving it to bike owners or mechanics to develop their own standards.

Roman F. Beck, a bicycle-accident forensic expert in San Diego, worries that the growing inventory of older secondhand bikes will become a ticking time bomb, especially now that the material has become pervasive in bike manufacturing. He cites even top-of-the-line mountain bike makers known for premium quality. “As good as [many] frames are, what happens when someone rides five or ten or 20 years from now?” Beck says. “Mountain bikes take a lot of punishment, but nobody knows how long these frames will last in that environment.”

And because no one tracks how often carbon-fiber bike components fail, Beck says there’s no way to determine how widespread the problem has become.

First used in aircraft dating back to the 1960s, carbon fiber made its way to bike parts in the 1970s, as manufacturers discovered its vast potential for cutting weight. French bike builder Look produced a carbon-fiber frame in 1986, and it gained widespread attention when Greg LeMond won the Tour de France with it. A few years later, however, the world’s first mass-produced carbon-fiber frame, the Trek 5000, suffered so many problems following its 1989 release that the company discontinued the model after a year.

But Trek didn’t give up. Learning from its errors, the company released a new carbon-fiber bike in 1992 using its “Optimum Compaction, Low Void” technology and has been using the material ever since. Other bike manufacturers soon figured out their own carbon-fiber processes; in the 1990s, they began selling parts and entire bikes made from the material, mostly at exorbitant costs and for use in professional racing.

By the mid-2000s, carbon fiber became widespread in the industry, not just in race bikes but in everything from commuters to mountain bikes. Components like front forks and handlebars built from the material can now be bought for under $100 and entire bikes for less than $2,000.

Since then, there have been several recalls related to the material. In 2009, for instance, Mavic recalled its R-SYS carbon-fiber wheel rims after reports that they were shattering. In 2010, the bicycle magazine VeloNews reported that several racers riding on Trek Madone 6-Series bikes suffered crashes after the failure of carbon-fiber steerer tubes, the part that connects the frame to the handlebars. In response, Trek said the problem came from installation and compatibility issues. The company didn’t recall the bike but worked with the Consumer Product Safety Commission on a consumer alert.

Matt Shriver, Trek’s Belgium-based technical director, says manufacturing can’t always be to blame for carbon-fiber accidents. In the eight years that he’s worked with Trek’s race team, Shriver says he hasn’t seen one failure in a carbon-fiber frame that could be blamed on the way it was built. In a widely reported crash in February involving a Trek Domane carbon-fiber frame that split in half, Shriver says Trek’s engineering department sent him a link to an article, asking if the cause could be a manufacturing defect. “I looked into it, and it turns out a guy fell on the frame during the crash,” Shriver says. “That’s the kind of impact that could cause any material to break.”

There’s already a cottage industry of people who specialize in lawsuits resulting from bike accidents, including a growing cadre of attorneys and forensic experts who specialize in carbon fiber.

Like other manufacturers, Trek maintains that its carbon-fiber components and bikes are safe. The company’s warranty, however, extends only to the primary user. Shriver says that buyers looking into secondhand parts and frames should make sure they were serviced correctly. To examine the quality of used carbon-fiber bikes, some mechanics have begun conducting the “white glove test,” which involves wiping carbon-fiber parts with a cotton glove—if the glove snags along the way, it could signal that the carbon has been damaged. Others tap carbon-fiber frames with a coin, listening for a change in pitch that might signal a crack.

Yet even those approaches don’t ensure buyers that they’re getting a used bike without hidden damage. Elrath, the bike-accident expert, says the most effective way to inspect carbon fiber is to send it to one of a couple companies in the country that can conduct an ultrasonic scan—a checkup that often costs $350 and might lead to repairs that could run upwards of $1,000. Not the kind of fees, in other words, that most buyers in the market for a used bike are likely willing to pay.

It’s important to note that some of the experts on carbon fiber-related accidents I spoke with haven’t concluded that the material is patently unsafe. Instead, they say the consequences of shoddy manufacturing and wear and tear underscore the importance of buying from a reputable manufacturer and assuring the bike is inspected regularly by someone trained to maintain carbon components. Even after the lawsuits he’s seen, attorney James Reed, the New York Bike Law representative, still rides two carbon-fiber bikes, a Trek Madone road bike and a Giant mountain bike.

Andrew Juskaitis, Giant’s U.S.-based global product marketing manager, couldn’t talk about the specifics of the Kowal case but told me that when bikes and components fail due to manufacturing defects, the company stands by them and will offer replacements. Carbon-fiber components have sometimes failed, Juskaitis conceded, but he said that’s simply the reality of bike building. “Like any material, carbon fiber has a fatigue rate, just like steel or aluminum or titanium or anything,” he said. “No maintenance can keep a frame from fatiguing eventually.” In cases where Giant’s manufacturing is responsible, Juskaitis says the company will negotiate “to make things right.”

For Kowal, whose Giant front fork broke beneath her in the ride across Iowa, settlement negotiations are underway. If they can’t reach a settlement, the next step will be a “destructive test” of Kowal’s bike, which has been kept in storage. The exam, according to attorney Hoffman, will involve hiring a forensic expert to analyze the fork’s material to see if it was too thin or manufactured with defective gaps.

If Kowal’s lawsuit goes to trial and she wins against Giant of Taiwan, the victory won’t necessarily set a precedent for other cases, especially outside Illinois. But no matter how the case ends, the appeals court ruling in Kowal’s favor may embolden other attorneys to go after foreign bike manufacturers and the U.S.-based companies they set up to distribute, using the same arguments Kowal made in her case.

The question now is just how many others will be hurt by carbon-fiber bike components failing, Elrath says. An avid cyclist, he rides a carbon-fiber bike—but it’s one he built himself, adding additional material at high-stress junctions. He knows others were built with far lower standards.

“It’s completely reasonable for someone who wants a lightweight bike to look at carbon fiber, but they need to understand the risks,” Elrath says. “Absolutely this is getting ignored.”