It's the LAW, son!
Back in the old days, when ESPN was a new, unproven network, they didn't have all of the major sports contracts that they have now. And, they didn't have all of the sports talk shows and recaps and countdowns shows, etc.
In order to fill the void between the few major sports programs they did have, the programmers at ESPN covered some fairly little-known fringe sports. I spent many an enjoyable hour, back then, watching the World Curling Championships, Unlimited Hydroplane boat racing and such.
But, my favorite thing to watch was Gravity Bicycle Racing. It seemed like every race they showed was in California, and they may have all been. For all I know, that might have been the only place in the world where these guys ever raced.
The bikes were cool, custom built and low to the ground. They looked like miniature road-racing motorbikes, without an engine. The bikes had full racing bodywork. And, the racers wore full leathers, and full-faced helmets. That was probably for the best, since the bikes would hit speeds of 65 mph and higher on some of the long downhill race courses.
I don't know if there are still sanctioned downhill gravity races. I know that I don't ever see it listed in the programming guide on ESPN, nowadays.
There seems to be a resurgence in the grass roots level of gravity racing, though. I see some cool modified bmx framed gravity bikes, here and there, on the interwebs. And, there are a few purpose-built custom gravity rigs floating around out there, as well.
I might have to build myself one, eventually. We have a few hills, in Colorado. I'm sure I could find somewhere to ride one...