You may need a boot fitter. Most racers have orthotics for footbeds and some had to have extensive fitting due to genetics or injury. This information is a guide, not gospel.

FLEX – Boots start below 80 and depending on sex, weight, and ability the flex will be somewhere 90 – 150. at 200-250 a 120-130 flex for me. Some boots Flex can be adjusted. The second figure shows flex as the line forward of ankle towards the COM (Center of Mass).

CUFF CANTING – A boot may have adjustments for cuff canting. This is a guide using a plumb bob. Other methods will work.

Lange has this method

LINER This method can be used the heat the liner to reform.