I have a rule of thumb that works for me when I have knee pain. If my knee hurts in the front I lower the seat, if it hurts in the back I raise it. I have also found that if my cleats are not adjusted perfectly I have real bad pain in my knees. I find the smallest things cause the worst pain. However I am not a doctor and I know what is best for me, which may be totaly wrong for you. Anytime I have aches and pains I try to self diagnose if that fails I look for help.