Back in the 70's when I was "sidecar" ice racing, we used #8 sheet metal screws. Screwed into knobby or trials tires from the outside. About 1000 screws per tire. They did not go all the way thru so holding air was not a problem. Last bike was Z1, 900 Kawasaki with home made sidecar on LEFT side. Rear wheel relaced from 18" to 16" for better tire choice. Traction on ice was as good as on pavement. Coming out of turns onto and down the straights, with hack man (monkey) draped over rear fender, front wheel would not touch the ice until throttle was closed. Lots of good memories from those days.