Personally I wouldnt be comfortable with him cycling near my home. My wife is not easilly shocked but was upset at some flasher on a train a few years ago.
Where do you draw the line?
If naked cycling is ok how about jumping out naked from behind bushes in a park? Then same question but next to a school?
The difference is the intent. The flasher intends distress, even harm (and there have been psych studies that shows a tendency to advance onto more serious sex offenses...)
Again, kids are going to see nudity at some point. A good parent will raise their kid to understand that there are many different types of people in this world, and that nudity isnt evil. Bad people are the things to worry about. I think possibly this guy may be misguided, I doubt he's harmful.
I always remember talking to a guy who used to go to nudist camps. He said its very easy to tell if someone is a true nudist, if they get a perverse kick something tends to "rise into view"...it gives them away.