ice tires

Good luck finding Trelleborg's. It seems that everyone knows where to get them, but they just can't get them. There's a couple places that sell studded tires. One is www.winterstuds.com can't remember the other though.

I believe the series you're running will let you use ice screws in your tires. I've got a set of ice racing tires that use 1" Kold Kutter screws and street bike tires for a liner. Cost is about the same as a ggod set of studded tires

If you're really on a budget, you could use shorter sheet-metal screws from a hardware store. They won't last very long and you'll get lots of practice changing them.