I stopped into a snowmobile place to look at the studs they screw into snowmobile tracks for ice racing and the like. They could only show me what was in a catalog. There were several different types, and some looked interesting.
I didn't pursue it and just forgot about it... if you go this route let me know how they work. Here's how some dirt bikers use them:
http://www.snowmobiletrails.com/moto/index.html