I got an email, today, from Jesse Swift, with a picture of a pretty cool Gravity Bike attached. A Gravity Bike is a bike, with no crank or chain, designed to be raced on a downhill road course.
Back in the mid-80s, before ESPN became the powerhouse sports network that it is, it was a lot more entertaining to me. Since they didn't have the major sports leagues under contract, the
ESPN programmers had to be pretty creative to fill the broadcast day. There was a lot of curling, and Unlimited Hydroplane boat racing, and such on the air, pretty much every day.
One of the fringe sports which got a fair amount of coverage was Gravity Racing. It was a big enough niche, then, that there were actually commercially-available Gravity Bikes from a few bmx manufacturers (pretty much the same guys who were involved in Formula One bike racing). These were, essentially, bmx bikes, with rear pegs, clip-on handlebars, low-slung motorcycle-style seats and full-coverage fairings. They really looked like little racing motorcycles, sans motor.
Predating this by about 10 years, I "pioneered" gravity racing in my neighborhood. I had broken the crank on my poor little purple Buzz Bike, and was saving up to replace it. But, I still wanted to go to the trails and hit the jumps.
So, I fashioned foot pegs for it, by removing the one-piece Ashatabula crank and the bottom bracket, then jamming a piece of two by four, split down to fit, through the bb shell. I pushed the bike over to The Trails, and to the top of the downhill portion. Then, I pushed off and let gravity accelerate me up to jumping speed. It was a little scary, since I had no brakes (coaster brake only), but it worked like a charm.
The first run, it worked like a charm, anyway.
On the second run, on the third jump down the hill, my wooden foot peg snapped in half. For once, though, I managed to not crash. But, I did get...shall we say...intimate with the banana seat. That was the end of that particular experiment.
I waited another couple of weeks until I had the money for a new crank, then resumed my dirt-jumping activities.