When you think of Memphis, you probably think of Elvis, FedEx, or maybe on a more somber note, the assassination of Martin Luther King Jr.

So you might be surprised to learn that Memphis is also becoming one of America's great bicycle towns. Three urban scholars (Kevin Smiley of Rice University, Wanda Rushing of the University of Memphis, and Michele Scott of North Carolina State) share the story of this unlikely development in a new issue of Urban Studies, and consider what it means for the city's future.

A quick bio on Memphis: Years of interstate expansion, urban renewal, and white middle-class flight took a big toll on the city center. City population has been on the decline, despite annexations designed to add residents. The poverty rate exceeded 28 percent as of late 2013, the highest in the nation among major metros. It's the story of so many American cities, to a slightly greater degree.

A few years ago, Memphis didn't have much going for it in the bike department, either. In 2008, Bicycling magazine named the city one of America's three worst for cycling. The following year the city ranked 69th out of 70 large U.S. cities for bike commuting—beating out only Plano, Texas. "In Memphis, bicycling was an afterthought," write Smiley and his co-authors.

Yet this changed with the 2010 opening of the Shelby Farms Greenline, a 6.5-mile rails-to-trails route for walkers and cyclists that runs through the center of town. Despite little support from local officials, project advocates made the idea a reality through private donations and a federal grant. The greenline became an instant hit. One city council member who'd initially opposed the trail said "I've never been so wrong in my life"; it ranked second on a Best of Memphis 2011 list, ahead of a local appearance by Barack Obama.

Bikes quickly became a rallying cry for a struggling city. City officials came on board, led by Mayor AC Wharton, a strong bike supporter. Local cycling advocates were empowered as well. Together these forces championed a 2010 plan to build more than 50 miles of bike lanes in a couple years. When city engineers left the lanes out of a street design plan, Wharton pushed back—with bike advocates behind him—until they were included.

In 2012, Bicycling magazine reversed course and called Memphis the country's most improved city for cycling. And Mayor Wharton told the New York Times, "We need to make biking part of our DNA."

As an up-and-coming bike city, Memphis had a new cultural reputation—and more importantly, a positive one. Bike advocates saw the emerging cycling network as a way to improve social connectivity across the city. Local businesses and developers found ways to leverage cycling into economic growth. Bikes became the centerpiece of what Smiley and company called "a new urban development regime."

But with the future in mind, the researchers are quick to point out the potential drawbacks of such a rapid social shift. Take the city's Harahan bridge project. Efforts are underway to repurpose the former road connecting Memphis with Arkansas across the Mississippi for cyclists and pedestrians. The bridge is backed by a $15 million federal TIGER grant and has encouraged many local businesses.

Exciting as the Harahan project is for city mobility and economic development, Smiley and colleagues point to evidence that it's already leading to gentrification in adjacent neighborhoods. The census tract closest to the corridor was 54 percent white and 43 percent black in 2000; by 2008-2012 figures, it was 66 percent white and 14 percent black. That's an unsettling demographic shift, especially in an area that's home to the National Civil Rights Museum.

The researchers caution (citations omitted):

The Harahan plan seeks to achieve changes in the image and ultimately the place character of Memphis. Without a commitment to social preservation of place, however, the gentrification evidenced over the last decade may be furthered with the installation of the Harahan, thereby undermining the goals associated with utilising bicycling as a civic change agent.

According to the authors, the message out of Memphis is both "hopeful" and "sobering." On one hand, the rise of cycling has done a lot of good for a troubled city at a cash-strapped time. On the other, not everyone is benefiting equally from the shift, and some of the neediest residents might even have suffered as a result. Onward and hopefully upward, on two wheels.