Most advanced level boots combine multi density materials to make boots stiff in critical areas of energy transfer but soft in other areas.
Ski boots stiff vs soft.
Stiff vs soft flex.
A boot needs to be stiff enough to support the skier s tall neutral stance the too soft boot will collapse under the weight and leverage of the skier creating too much bend in the knee and resulting in smoking quads.
Soft boots create a more free flowing experience and are meant for riders looking to seamlessly float from one feature to the other.
Stiff boots on the other hand create a more aggressive posture that forces skiers onto their toes.
Ski boot flex is indicated by a number ranging from 50 very soft to 140 very stiff.
While the softest skis are popular only with beginner skiers most recreational skiers non racers choose a ski somewhere in between stiff and soft.
The higher the number the stiffer the boot.
Lightweight short and beginner skiers should start with softer flexes while larger taller and more aggressive skiers can use stiffer flexes.
I hard boot will hold back skill improvement way more than a soft boot will hurt an advanced skier.
Skiers who ski hard or who ski more than just a few days a year may desire a stiffer flex boot both because of the higher quality of materials as well as durability and ski ability of the boot.
If you have to ask you are probably better off getting a softer boot.
If in doubt use a softer flex to prevent pain and practices better technique before using stiffer ski boots.
If you think your shoes are too soft you can always bolt them.
Usually through trial and error but with some guiding parameters.
Stiff flex boots may also be appropriate for beginner and intermediate skiers who are taller heavier or stronger than the average skier.
A range of ankle dorsiflexory ankle motion of less than 10 degrees is.
Very stiff racing boots can be uncomfortably rigid for general use.
Soft skis don t go as fast as stiff skis but being easier to turn makes flexible skis more versatile than stiff skis.
Some boots offer features such as shock absorption for landing jumps or slamming bumps.