Those lime, orange and yellow bikes could double next month

First orange and green bikes, and now yellow bikes are for rent in Seattle. This month marked the U.S. debut for China-based bike share Ofo.

Ofo (yellow), LimeBike (green) and Spin (orange) are each permitted to have 1,000 bikes in the city. In September, the maximum increases to 2,000 bikes per company. The city will allow the companies to double their stock every month.

Seattle officials watched the city's Pronto program fail earlier this year. So far, though, the new privately-run system is getting good reviews. The private companies do plan for some bikes to be thrown in the bushes, broken or otherwise mistreated. But Derrick Ko, CEO of Spin, says there have been very few issues in Seattle.

"The past month, there are actually more people writing into us, saying, 'I really want this to work, I noticed that there's a damaged bike,'" Ko said. "We were really encouraged and really humbled by the response we received."

Ko says Spin wants to eventually have 10,000 bikes in Seattle, much larger than any of Spin’s other cities, or any bike share Seattle has had.

The Seattle Department of Transportation is piloting the bike share system for six months. Department spokesperson Mafara Hobson says ridership has outpaced even Pronto's busiest days. One big difference: riders can park the bikes on any sidewalk when they're done, instead of locking them at a specific station. Hobson says it’s viewed as a success so far, especially since there's no financial risk to the city.

Hobson: "While we're sort of evaluating and monitoring how this is working, there are no city funds going into the program; there's no waste of tax payer dollars and no financial loss."

Hobson says a fourth bike share could come to the city within the next couple of weeks.

Seattle's transportation department will decide in December whether to keep the bike share program open.