Gears. That’s the first thing you see when you walk into Peddler’s Creamery in downtown Los Angeles. Also wheels upon wheels and chains upon chains, strung together across the room and up and down walls to create an elaborate “kinetic sculpture,” as Edward Belden, the store’s babyfaced owner, calls it.

They might seem ornamental at first, a nod to Belden’s love of bicycling and hipster culture at large. Even the old Schwinn itself, hanging out in the corner of the store by a window and a brightly colored collage, might seem like a prop. Until you realize that everything is connected, and those chains and wheels travel the length of the store through the walls to the back, where they power an ice cream churner and literally make ice cream by bike power—as long as someone is peddling.

“This project is about bringing together three things I love: ice cream, bicycling, and creating a sustainable world,” Belden said. After getting a masters in environmental science, the earnest thirtysomething found himself working for a public research interest group. “But I wanted to think of a more creative way to reduce our footprint,” he told me. He’d never forgotten his first job, working for a Baskin Robbins, and his first bike, which he paid for by recycling cans and bottles.

So he quit his job and built a modified tricycle that churned ice cream while it peddled, then took it out on the streets of L.A. Soon Peddler’s Creamery became more than a trike; Belden opened a brick-and-mortar store in 2013, with a bike contraption that still churns all of the ice cream. “We want people to walk away knowing they consumed something that’s good for the planet but tastes amazing,” he said.

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How does it work? The chains travel from the modified bicycle’s gears across the shop and through the wall into the back, where Belden has hooked up a churner with a bucket chain that requires old-fashioned rock salt and human elbow (er, knee) grease to operate. The patent for this contraption is pending, and at some point Belden hopes to power the entire store not by electricity but by bike.

On any given day you’ll find customers snapping selfies on the bike, then realizing, “Hey, this thing actually does something!” It only takes 20 minutes to make a batch, and peddling a whole one earns you a free scoop of ice cream. That means everyone from the neighborhood comes to coast on the bike: government workers, young professionals, folks who live in the housing project upstairs, and, of course, the hipster bike enthusiasts with one pant leg rolled up. “I think it’s because of the ice cream,” Belden explained. After all, how could anyone resist banana-chocolate-chip, candied kumquat, and even maple-bacon-pancake, made with vegan bacon?

“It’s a healthier alternative,” Belden said. “You make and eat ice cream on a calorie-neutral and carbon-neutral budget.”