Anyone with both pedals and a joystick will probably have run into the default assignment conflict for the axis already (and may have even earned their "crash" award like me because of it LOL!). Somewhere I saw a post where a person was wondering about removing a default assignment that is applied where you don't want it because the "Clear Binding" option is initially greyed out. I believe the initial thought was we have to give the assignment something by changing it to another value. However, to clear it all together, first select any key or click action as if you were going to give it a new setting then click the "Clear Binding" button and finally the "Accept" button. That will change the control setting to "Unmapped".