Whats the difference between #4 and #6 flex on full tilts? I can't find the answer on the interwebs.. I just know that one Ski boot has a #4 flex tongue and the other has a #6 flex tongue.
Yep, like uncle sam said its on a scale from 1-10 where the higher number is stiffer. So if you want a stiffer boot go with the 6 but if you want softer go with the 4