I am eerily similar to the old guy boot question, but older still. I too have a pair of Nordica Grand Prix 90 boots and they are slowly breaking apart. The typical advice I see for a racer wannabe is stiff, stiffer, and stiffest. I skied yesterday on a pair of boots that were stiffer than by old Nordicas, but the forward lean was less and the stiffness made them really awkward feeling. From my skiing experience, I prefer to create a greater forward angle and less resistance to greater angulation. I am accustomed to creating significant forward pressure and generally encounter blistering on my shins early in the season.
Logic tells me there must be a range of stiffness or flex that racers accept. If stiffer were simply better, then boots can always be made stiffer even to the point of becoming completely rigid. There must be a happy middle. I understand that racers need lateral stiffness to the skis cannot twist and lose grip, but I don't see how that would be to any advantage to prevent skiers from bending their knees in an effort to reduce wind resistance.
I am your basic 5'6", 145 lb guy who likes to race. I need to replace these old Nordica GP 90s at some time. I don't think I'd be happy with those 130 boots that need heaters to put on and an hour in the lodge to take off. I was just watching World Cup racing and a commentator said one of the racers had a broken bone in his foot and consequently switched to a stiffer boot. I infer from this that he must not have been skiing on the stiffest boot possible.
What I am looking for is an explanation of how to choose boot flex that is broader than racers need really really stiff and beginner can have soft and comfortable boots. I understand no one wants boots than can flex from the inside to the outside edge. Is the front and back flex simply something that must accompany the side flex? I can well understand the 200 lb racer in 130 flex boots may well feel less resistance on his shins than I may at 145 lbs. I like the range of motion, being able to center my mass over my skis, resistance to flexing or forward pressure that I current have. How do I go about choosing my next boots?