I’m in New York this week, en route to Fortune’s annual Brainstorm Tech conference in Aspen, Colo., where I’ll be talking about “bike sharing” with Davis Wang, co-founder and CEO of China’s largest bike sharing venture, Mobike.

The concept of bike sharing has seized the imagination of global tech investors lately as a host of Chinese bike sharing ventures take their turbo-charged business models global. Mobike recently launched operations in Singapore, Japan and Manchester and is reportedly coming soon to Washington D.C. Arch-rival Ofo has rolled out in Singapore and Cambridge, England and vows to have operations in 20 countries outside China by the end of the year.

Can China’s bike sharing behemoths conquer the world?

In pondering that question, it helps to remember that bike sharing is an idea that was not made in China. The French city of La Rochelle created one of the first successful bike sharing programs in the 1970s. Cities in Denmark, the Netherlands, the United Kingdom experimented with community bike schemes throughout the 1990s. In the United States, Denver introduced the first citywide bike sharing program, called B-cycle, in 2010. About 60 U.S. cities now run bike sharing programs. The National Association of City Transportation Officials estimates the number of rides on U.S. bike sharing services–including Boston’s Hubway, Chicago’s Divvy, Washington D.C.’s Capital Bikeshare–topped 28 million last year. New York’s CitiBike program, the nation’s largest, provides more than a million rides a month.

If anything, the Chinese have come late to bike sharing. While bikes have been a crucial mode of transport in China’s cities since the Mao era, ridership declined steadily after the 1990s as China’s prospering middle class commuters traded up for passenger cars. That trend has been reversed only in recent months thanks to frantic competition among about 30 privately funded bike sharing startups, none of them launched before 2015.

But the power of those fledgling ventures is formidable. Consider the industry’s two heavyweights: Mobike (whose investors include Tencent, Foxconn, Singapore’s Temasek, Warburg Pincus and Sequoia Capital), and Ofo (backed by Alibaba, ride-sharing giant Didi Chuxing and Russia’s Digital Sky Technology). Both companies claim valuations in excess of a billion U.S. dollars. On peak days each now provides more than 25 million rides–almost as many as all the American bike sharing services put together provided all last year.

How did bike sharing in China get so big so fast? It helps that China has more people than the U.S., and that China’s cities are far more densely populated. But the critical factor is that unlike the U.S. and Europe, China’s brand of bike sharing embraces capitalism red in hub and spoke.