You are absolutely right and I have had a serious word with myself about lax use of terms - they are Polyurethane - NOT PVC.... Not the same thing at all.
Won't use the self adhesive Treadmaster pads as not sure what type of glue they use? Will check out some of the links provided here though - thanks everyone! Still intrigued as to what the Redbays use on their tubes though?
Thanks for the help so far though!!