I've been riding for approx. 2 months now and am having trouble with my knees. As I've heard, I try to "sit down in the saddle" when I ride but still experience some major muscle exhaustion in my lower quads and around my knees after about ½ a turn around the block. I realize most of it is simply being out of shape (I'm 6' and 285 lbs. - old football weight of course). But shouldn't it be getting better? Days after I ride, I still have major soreness under my kneecaps. I wonder if I'm causing damage or just need to keep going until I find "in shape". Any "doctors" out there with an opinion? Sure am looking forward to being able to ride a distance someday.