Boot doctor: Does ski boot flex matter?

“I find it hard to flex forward in my boots.Have I bought the wrong flex for my ski level? What can be done?”

Answer: The flex is there to help determine the level of the boot and it relates to how easy it is to flex forwards. It is important to remember that there is no generic way of testing a boot’s flex. Plastics vary greatly between different brands, so what one brand calls a 120 flex, can be very different to a 120 from another brand. The flex should only be used as a guide. Typically, the more aggressive the skier is, the higher the flex should be.

When you buy a ski boot you also need to take into account your ankle flexion, your height and weight. Someone with limited ankle flexion will benefit from a slightly stiffer boot, as does someone that has too much ankle flexion. If you have limited ankle flexion you will need a heel lift to be able to ski in the optimum position. A skier who is very tall will have much more leverage to flex a boot than someone who is shorter, so will need a higher flex to compensate this. Also heavier skiers put more weight on the plastics so a stiffer boot may be required to offer resistance.

Many boots give the option to change the flex of the boot.  Some have two screws in the spine, so removing a screw allows more flexion. Other ski boots have a soft/hard; sport/performance option in the spine of the boot.

For extreme cases it is worth visiting a boot fitter who can cut ‘V’ shapes into the plastic shell and remove plastic that offers resistance. This will drastically increase the flex.