I took the wheels off my small skid (case 1816) to have the rims sandblasted/painted and have these new snow tires put on. This is a very light skid and only minimal use around home here. I noticed upon taking old tires off each had a inner-tube. Do the thires have to have inner-tubes? if so, any make (I/E walmart,Napa..) or best to get certain ones from certain place? P.S. they look like regular tubes.. But been years since I ever had anything with tubes.