They used to race motorcycles on the ice at Crystal Lake here in Manchester N.H.They were still doing it in the early 70's,because I drove there,and I got my license in 72.It's about 20 miles from me.The studs they used were just carriage bolts,short enough so the nuts were really the studs.At the start of the race the rooster tails were pretty spectacular,but after a couple of laps the riders really showed their skills.Then they were riding in the ruts,it looked like they were riding on giant corduroy.All six bikes handlebars were in a constant hard shimmy.They looked like speedway racers,they were sideways all the time,with the front and rear wheels facing two different directions.The races were round,no straightaways,just a circle.