MINNEAPOLIS (WCCO) – Monday is Earth Day, and those green Nice Ride bikes are back on Minneapolis streets.

The iconic green bikes, which debuted in 2010, made their spring return Monday, as did the blue dockless bikes that rolled out last fall.

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In honor of Earth Day, you can take a Nice Ride bike for free. Just use the promo code “earthday19” in the Nice Ride app.

There are also some changes to Nice Ride this year.

For starters, the green bikes are only available in Minneapolis; St. Paul is working on its own bike-sharing program.

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Another change is in the works: Nice Ride is planning to roll out e-bikes.

The blacked-colored e-bikes will be located at docking stations around the city, and they’ll replace some green bikes.

E-bikes are not scooters. Instead, they are bikes with electric components that help riders have an easier time with hills and strong headwinds.

“The motor only kicks in if you’re peddling,” said Bill Dosset, of Nice Ride. “So it kicks in when you need it in a really smooth way.”

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Right now there is a recall of the electric bikes because of a brake problem. As such, it’s unclear when Nice Ride will roll them out.