The Stock ones don't seem to hold up. There are a few differant brands out there. From experience with the solid aluminum ones they seem to fill up with debris and collect sticks and rocks which can and will cut the boots. When they were on the grizz it was habit to clean them out everytime we stopped. 700km with the guards had to change three boots.... another guy we ride with removed all the a-arm guards put on 1000 plus km on his quad and never did a boot and road all the same terrain.