I posted this in response to Swine, but I'll repost it here:

If you think this is shocking, you probably aren't familiar with flat track... mile flat tracks, to be more exact. Motorcycle history lesson time:

Back in the day, to be the American national champion, you had to be points-leader in all of the Grand National events. At one time, this included almost everything you could do on a motorcycle: TT (a combo of motocross and dirt track), road racing, and flat track. You had to succeed in all events to get the national #1 plate. [tinyurl.com]

In America, flat track racing was huge in the late 60s through the 70s. Like, as big as NASCAR. Huge venues with huge crowds. The tracks were somewhat similar - dirt ovals of varying size, usually between 1/4 and 1 mi. The series would visit all sorts of tracks, but the real ball-breaker events were the "mile" races. The mile tracks were crazy fast - over 130mph on the straights, and something like 80mph+ in the turns (which are taken in a constant slide). Oh, and you get no front brake and lining the track is a wooden fence or wall which, if you're lucky, may have a few haphazard hay bails in front of it for "padding."

Anyway, before you watch the video, you should read the first half of this so you understand what's going on: [www.superbikeplanet.com] If you're too lazy for that, the Cliff's notes: King Kenny Roberts was/is one of the best riders of all time, the bike is a TZ750 flat track racer custom built by literal two stroke tuning legend Kel Carruthers. The engine is a completely insane I4 750cc two stroke (let that sink in) which made somewhere north of 130hp at the top of the powerband. Remember, this is 1975; that kind of power is absolutely astronomical at the time - a modern 600cc race bike, heavily tuned, will put out about that much. Of course, this is a two stroke I4 though. It hits hard and doesn't let up; if you've never ridden one it's really hard to understand, but essentially imagine the most brutally aggressive fourstroke engine you've ever known, then double the aggression and cut the traction in half. It was impossible to ride.