2017 was the summer of the dockless bike share in Seattle. After city’s Department of Transportation enacted a yearlong pilot program that allowed companies to deploy fleets in the city, a blur of colorful new bikes appeared along bike trails: orange Spins, yellow Ofos, green Limes. As brands competed with one another for customer loyalty, Seattleites enjoyed free rides to breweries, parks, and summer barbecues.

After the end of the pilot, the city unveiled new permitting rules, which required each operator to pay $250,000 upfront to operate in the city. The great culling began: Ofo announced the end of its Seattle operations, and Spin bowed out too, saying it wanted to focus on electric scooters. Lime was left the local victor. A few months later, Lime announced it was replacing its standard bikes with the company’s electric model. In the space of a few months, thousands of bikes around Seattle disappeared. And in dozens of other cities across the U.S., dockless bike share has swooped in and out or pivoted to scooters. The companies that stick around frequently introduce new models. As old models are phased out, it’s worth paying attention to what companies are doing with the leftovers.

In 2018, Seattle’s Basel Action Network, an environmental nonprofit, placed GPS locators on three out-of-commission bikes: a Lime bike, which was repaired and put back out onto the street, and two Spin bikes, last tracked to two scrapyards. The scrapyard seems to be a common fate for these bikes; mountains of bikes have been spotted at scrapyards in cities like San Diego, Dallas, Los Angeles, and Reno, Nevada.

Basel Action Network, which is known for its work on electronic waste, began tracking bikes out of concern that each contains GPS trackers and circuitry in the locking mechanisms that should be disposed of safely through electronics recycling. “We started seeing more and more [bikes] that were just mangled, that were vandalized; people were dropping them off bridges, just to see what happened,” says Jim Puckett, the founder and executive director of BAN. (People around the world seem to find joy in throwing bikes and scooters into waterways.) “So I inquired pretty early on with LimeBike and asked, ‘What’s your recycling policy?’ ” Puckett says he’s never heard back from Lime.

One Nicaraguan school has even outfitted a bike with a metal cart in the back to create a pedicab that can hold three children.

A Lime representative I spoke with emphasized the company’s dedication to sustainability and said that it removes batteries before transporting bikes to “a facility that specializes in the handling of iron and steel” (a very fancy way of saying “scrapyard”). I contacted three scrapyards where dockless bikes have been spotted to ask how they typically handle bikes at their facilities, but none returned my calls. BAN’s Puckett, however, says that metals recyclers “are not typically isolating the electronics” and that companies should adopt explicit policies about how they recycle their bikes to ensure that all components are disposed of properly.

Lime also says it “transfers” retired bikes to other locations and has considered donating bikes, though a spokesperson declined to give me examples of where donations have ended up. But hundreds of other dockless share bikes have found new life as donations or purchases that benefit nonprofits.

Spin, for instance, has a partnership with Christian humanitarian group World Vision, and according to a press release it provided, those gifts have been sent to “underprivileged kids overseas,” though there are no specifics on where. It’s also partnered with Wisconsin/Nicaragua Partners, a nonprofit headquartered at the University of Wisconsin–Stevens Point. The space it rents was close to the university’s sustainability office, which coordinated Spin bikes on campus, so when Spin decided to leave the university scene, W/NP stepped in to request the bikes.

So far, it’s sent more than 100 bikes to Nicaragua. Thirty of those are being used by local firefighters for their commute, and the rest are with local learning centers. “The bicycles have been very useful for the people of Nicaragua,” says Mirna Angulo, a W/NP administrator in Managua. “Some are used for students who travel long distances to school, rental to people for running errands, and [they] provide some alternative transportation to take people to nearby locations.” One school, she says, has even outfitted a bike with a metal cart in the back to create a pedicab that can hold three children.

Ofo, too, donated bikes after the company hastily moved out of the U.S. last year. That’s how Kurt Kaminer, founder of the Bike Share Museum, has gotten the two Ofos to start his collection. (He’s contacted Spin and Lime to see if he can get his hands on retired models, but no luck yet.) One he got from Bike305, a bike initiative in Florida’s Miami-Dade County that received hundreds of Ofo bikes. The other was from a similarly enormous fleet gifted to Bikes for Tykes, a charity in Richland Hills, a city just outside Fort Worth, Texas. But a friend Kaminer met on a bike forum told him that because the bikes were too big for most kids to ride, Bikes for Tykes looked for other outlets for the 500 donated Ofos. Eventually, says Kaminer, a local auto parts store offered to store about 350 remaining bikes, sell them, and donate the proceeds to Bikes for Tykes. Sure enough, a Dallas Craigslist search brought up an ad (now expired) selling Ofos for $65, or a two-for-$100 deal. The address listed matches Steve’s Certified Auto Repair. I called Steve’s, and the receptionist there confirmed that it still has about 150 bikes for sale. Get ’em while you can—it’s a steal for any bike, especially a sturdy beast like an Ofo. Plus, Kaminer recently put together a guide for how to maintain them, so you can keep your rescued bike in tip-top shape.

You might see Ofos floating around outside the U.S. as well. Simon, a cycling enthusiast who lives outside Nottingham, U.K., saw one for sale for 80 pounds, and he “couldn’t resist,” he says, given the quality of the bike components. His rescued Ofo became one of his nine bikes. “The owner of the shop told me he’d bought a few Ofo bikes cheaply,” he says. “I believe that too many were imported into the U.K. and the surplus bikes are being sold off cheaply.” And in Myanmar, a wealthy benefactor bought 10,000 discarded bikes for about $35 each from Singapore and Malaysia and distributed them to schoolchildren.

Whether companies donate, scrap, or just abandon their older models, Kaminer wants his Bike Share Museum to capture the evolution of the industry. “I realized it would be nice to preserve one example of each,” he says. Many citizens, frustrated with the number of bikes or scooters blocking sidewalks and filling scrapyards, think of them as litter or trash, but we might feel differently about them in retrospect. Kaminer says, “Eventually, maybe 10 to 20 years from now, they may not be out there, and people may not remember there was this service, and that this is what they looked like.”

Future Tense is a partnership of Slate, New America, and Arizona State University that examines emerging technologies, public policy, and society.