Originally Posted by Ag&Au
I think those are a kind of sacrificial skid plate to make a bunch of noise and warn you that if you continue your present ways, you will most likely bend the frame. I stuck them fairly deep into a sandy soil perm once, because they failed to screech in that soil. They cut right into it like a knife. I have found that the 16 inch tires and wheels help that clearance a surprising amount.
You really only gain 1/2" more clearance with the 16" wheels, but 1/2" clearance could be the difference between clearing the obstacle or a catastrophe...
In the back I regularly dig dirt with those reinforcements with no I'll consequences. The driveway thing is the result of 2 other things- us having a monsoon right now ( it is too wet/muddy in the back- I will get stuck) and recently getting low tree limbs cut so the trailer would fit under.