This is another alternative although I don't have any experience with them. Sorry I forgot how to do the link so copy and paste. The first is the company and the other 2 are articles.
http://www.wheel-works.com/
http://www.motorcyclecruiser.com/tech/t ... tire_seal/
http://www.streetchopperweb.com/tech/01 ... ke_wheels/
Cheers!