Why a used cage? is your butt not worth the price of a new one? Most used cages are JUNK,and you ruin what ever strenth they have when you cut it down, but if you insist on using one,be sure and check the inside of the tubing, that is where they rust.
Think about this if some one has a cage where is it stored, most likely out side with weeds growing up it,and how long has it been there?
I do not like used cages, belts,seats,and window nets,
Bill Fisher