I have had knee issues before. Pain in front of and below the kneecap is caused by the seat being too low. Pain behind the knee is from the seat being too high.
__________________
Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --
the tiniest sprinter