Snapped my ACL skiing 2 years ago. After surgery I rode my trainer as part of rehab. When I really pushed it I would get the same feeling - it was patella tendonitis. 2 things helped; rest/ice and ibuprofen. Not being the type to rest for very long, I would opt for "Vitamin I" - 600 mgs 3-4 times per day. After a couple days it was gone. That being said, I would see a knee doc before I did more damage. Sure, a bike fitting and a few adjustments might do the trick, but what if it's something physical? A fitting or adjustment isn't going to do you any good and it may do more damage. Here is a great knee web sight with a lot of information, the forums are a great place to ask questions - Good Luck! - Craig

http://www.kneeguru.co.uk/