Hello, Purchased new tubes for the tires I'm putting on my 4400. They have a flat piece of steel with a slight bend on each end of them and also a nut. They obviously fit over the stem and then the nut threads on. It appears they must go on the inside of the rim, there is not enough thread to mount them on the outside. Is it critical they be used? Are they for all types of rims? It seems they could cause problems with the tube. (mine are stock 1954 rims)Thank you, Scott