Burning cash

Jeffrey Towson, a professor of investing at Peking University, said "economic reality is being suspended" as rivals burn cash to grab turf.

"I think they're going to pull it off. A lot of businesses start this way: you have lightning in a bottle, a hot app, and you build a more sustainable business as you go," he explained.

Weaker entrants will drop out or be absorbed, Towson added.

China's government singled out Mobike and Ofo last month - praising bike-sharing as a means of cutting emissions and traffic.

Ofo launched in Singapore in recent weeks, and is now eyeing US and European markets. Mobike plans to enter Singapore within weeks.

Analysts said regulatory issues, logistics, and lower use of mobile payments overseas could brake expansion.

Lower winter ridership and losses from damage and theft also will weigh on bottom lines, they add, but insist the future appears bright.

Both Mobike and Ofo loftily envision tens of millions of connected bikes worldwide.

"It has only just begun," said Ofo's Zhang. "We hope to fulfill this vision in the next two to three years."