Step 3 – Shell check
Before trying any boot with the liner in, a professional fitter removes the liner entirely and has you stand in the shell only. This is the most important technical step in the fitting process and one that separates specialist fitters from generalists.
The shell check reveals the true internal volume of the boot and confirms whether the length and width are appropriate before committing to a full try-on. Up to 20mm of space behind the heel in the shell is the standard measurement for an accurate “sporty” fit as we like to call it. 10mm and under is considered an “aggressive” performance focused fit. 30mm and over is too large and the boot will be unsuitable to ski in.