I went with a friend of mine to the Schwinn Dealership in the mid to late 70's. I can't remember the exact year. Never the less, he bought a brand new Schwinn Sting. They had just come on the market.
If I remember correctly, it was, if not the best and most expensive BMX bicycle around, it was one of them. He was the third person in Spokane Washington to buy one. I could swear he paid over $500.00 for it. This was somewhere around 40 years ago. I was amazed at the price! He was into racing and ranked pretty high in the state.
He was the first person I saw make a Ice riding bike. He drilled holes in the tires and put little machine screws through them with nuts. He had sharpened them to a point also. It worked great, it was hard to wipe out on the ice after that.