And very dangerous on snow free roads.
there are ice studs, for riding on ponds, and road studs that are safe and legal(with limitations) for the road
I drilled stud pockets, and inserted standard automotive studs
notice only studs in the center knobs, you never lean more than that on icy roads, but if you happen upon dry roads, you have stud free rubber at the extremes. unlike car tires that have molded stud pockets, the first few miles with drilled pockets, are sketchy till the studs seat.
the result was mixed, front tire hooked up good, but my 1000cc engine was too much for the rear, I threw nearly all the studs by the end of the season, while not loosing even 1 on the front tire
the next winter season, I went to the darkside, kept the same studded front (which ended up lasting 4 seasons/20k miles) and a winter car tire in back, successful beyond my wildest imagination, riding in freezing rain and blizzards