You can balance them like any other tire just put weights in them. The tires are not made wrong and as long as you put glue in the bead track you are fine. use a hair dryer to heat the inside foam let it expand and settle then put it on a tire balancer and weight it from their. i know you have already glued your tires but for your next set remember to cut the edge of the foam . if you look at the inside of the tire it is roundish and not square like the foam comes. that will help to balance it.