The World Naked Bike Ride in Portland happened this weekend. Is it really about environmental awareness, or is it just a bunch of free spirited people who like to ride a bike nude?

Thousands of bikers around the world traded their bike shorts for their birthday suits on Saturday night for the 8th annual Naked Bike Ride. Enjoy the show after the jump.

The ride's organizers have been encouraging people to get naked since 2004.

"This is just a way of drawing attention to the need to be more green and replace fossil fuels with natural power,” Ken Johnson, who was body-painted grey at the Portland route, told Reuters.

In Portland cops even sent out a press release stressing it is legal to be naked in public in that city. They did, however, urge participants to wear a helmet, and a smile. If you have never made it to a naked bike ride, check out the video.