How far should you be able to lean forward in a ski boot? When you do, how much space should there be down the back of your calf?
If the flex is not hard enough, what can you do about it?
How much flex should a ski boot have?
There really is no definitive answer to that question. How stiff your boots are, like with skis, is a personal preference. Generally, higher performance boots will be stiffer but with all the Terrain Park Skiing going on there are a whole bunch of high performance ski boots being made that are softer. As far as space around your calf, there really should be very little but your ankles are more important to consider. Your ankle should have very little movement and your heel should not come up off the bottom of the boot. If your ankle is secure then the space around your calf will matter less
Reply:The guy who answered before me is right on. That being said, there are, sometimes, with some models of boots, things that can be done to stiffen them up. Each company varies in how they make stiffness adjusters. Some models have built in adjustment features; Knobs, or little screws that can be adjusted. Some boots come with "inserts" designed to be placed in certain slots on the tongue or shell, to increase stiffness.
If you already have a pair of boots which you want to firm up, bring them to a highly recommended or qualified bootfitter and see if you have any options. Otherwise you'll have to buck down and buy some. Keep in mind that owning your own good, proper fitting boots are the best thing you can do to improve your skiing. You can always rent good skis but it's real hard to get good rental boots which suit you 100%.
As a last resort for increasing overall stiffness, you can encase your old boots in quick drying cement; however the tradeoff will be that the extra weight might slow you down a bit.
Reply:The more flex you have the more foregiving the boot is which makes it more of a entry level to mid level boot. If it doesn't flex much, it's a higher end boot. The stiffer boots allows the skier to be more as one with the skis and doesn't have extra slop. Some of this is personnal preference. Some boots come with stiffener shims, if not you'll need to buy a stiffer boot if that's what you're looking for.
Reply:None, but I like the concrete idea.