Instead of adjusting your seat height based on being able to touch the ground while in the saddle, I would think it's MORE important to create the best distance between your "down pedal" and your seat. Nothing to do with where the ground is. In other words- maybe it's more important to create a good leg postion when your at your extended (pedal down) leg position. Just a thought: Riding all the time with your knees bent too much so that you are able to balance on your toes at a stop light has little to do with being a pain free biker for hours on end while riding. I'm not saying that's what's causing your problem, but it seems to me you are basing your saddle height on ground level instead of on good leg/knee angle. Maybe I'm wrong. But all angles are worth persuing!