see a sports med knee specialist. get an MRI. don't expect commentary from lay people in a bike forum to be in the least bit applicable to your own medical reality.

Look, I'm not trying to be a jerk but trying to play internet doc or expecting others to convey their own internet doc "wisdom" to any positive effect is just foolish. You MAY stumble onto a "truth" but you are FAR more likely to a) waste your time and/or b) misdiagnose and further exacerbate your problem. The only really effective solution is to bite the bullet and get an exam and an MRI to see exactly what is going on inside. If you are serious about cycling (and about your knee health in general) you shouldn't put the slightest faith in what anyone here has to say diagnostically (me included) and you should be making an appointment w/ a qualified specialist.

BTW - I work in the Orthopedic industry and even w/ all the experience I have I could theorize all day long but it is ultimately meaningless w/o actually examining you....