beachboy:

RE: roadwheel spacers and 'tires' - why not use a section of heat-shrink tubing instead of tape? This way there is no seam, and the if chosen right, it'll shrink down to hold the inner piece in place as well and hide the seam. Just remember to cut it a fair amount over-wide, as it shrinks lengthwise as well as in diameter.

I've used this for tubing spacers before, and it works rather well. Never thought of using it for 'tires' but heck, I've got scraps of all sizes laying about (ex-computer tech, and we used it for lots of things...)