Boot bang happens when you're boots are too big around the calf. You're calf and front of your leg is slamming around the top of your boot when landing. Essentially, by putting padding in the front of your boot, you are tightening up your upper cuff. If you are still getting boot bang, you can add another spoiler to the back of your boot and it will tighten up the boot more, while giving you a little more forward lean. It will also keep you're heel in the cockpit of the boot better giving you more control. The biggest mistake people make when tightening boots is having the upper cuff loose and tightening the toe box to much. You should have the two upper cuff buckles tight and the bottom two buckles loose. All the bottom two buckles do is keep the shell waterproof. So, when putting on your boots, tighten the top two buckles, then do your power strap, then tighten your two lower buckles just enough to overlap the shell. Bootbang will subside and you will have much more control.