I have modifide Robert's responce because I feel that he has given a good explanation however his conclusion is wrong
I think this question falls just inside the on-topic circle you draw around your site. While it isn't specifically about riding, it is a problem that is somewhat unique to riders. That uniqueness makes it at least cautiously on-topic, in my opinion.
The slippery slope comes when trying to distinguish between "questions about riding" (on topic) and "questions that might be of interest to riders" (probably on topic even if that interest is only peripherally related to riding).
This site should be about bicycles and riding-related questions. It can realistically become an anything-of-possible-interest-to-riders site because of the tagging system. Whenever you gather a group of like-minded experts, there's a tendency for some to ask off-topic questions under the premise that "riders are interested in this stuff" or "riders would know the answer to this." So questions like:
- How can I get a job working with bicycles?
- How do you heal groin injuries?
- What is your favorite music to listen to while riding?
- What is your favorite riding movie?
...they start sounding like on-topic questions, when they really are.