A new study ranks Portland, Oregon as the best city in the country for naked biking. The cheeky results from LawnStarter were tied to the popularity of naked biking, cyclist-friendliness, nudist friendliness, climate and safety to come up with the list. Chicago came in second and Philadelphia came in number three on the recently released survey. The survey claims that there are 172 nudists for every 100,000 people in the Portland area and searches for naked bike rides in the city top 1,000 a month. Clothing-optional bike rides have been growing in popularity in various cities in the past sever…