this is one reason I do not like cordura fenders; becuase they NEVER hold a turn. You cannot get them to 'turn' and stay there., they always hand 'limp'.
Some would say, "oh, good! there's no resistance" . but, you want the fender to WANT to stay in the position that helps your knee. A turned leather fender will do this. A cordura fender will always want to hang in the easiest, most direct manner possible, and this is just the opposite of what you want for your knee comfort.
Admittedly, since it is made of a light fabric, it offers less resistance than a leather fender that is NOT turned. But, it can NEVER BE turned. It will never off total relief. It will always want to go back to it's free hanging position, especially if you post the trot.
AND, if you are in a position with a bucking horse, you will find that the lightweight fenders and stirrups are dangerous because they will not drop away from your foot, but rather hand up on your pants or your gripping foot, and be more likely to end up with your stuck on them, as your body flies off the horse, and you end up being dragged. A heavy stirrup is a safer stirrup.