http://www.mcmaster.com/#foam/=3j4u9r


You need to buy the right thickness's and then glue the layers together to create the proper width. Then use a hotwire, or a waterjet to cut out the donuts. Once you have made the donuts, you mount them on the rim, and use a tire truer to bring them to the proper diameter.

Good foam is expensive, so make sure you are ordering the right type of foam.

Shawn.