Bob Maddox, an artist and cabinet maker from Medford, Ore., has built a jet powered bicycle which can go at least 50 MPH (he predicts it can go 75 if anyone’s got the guts). “When you’re on a motorcycle going 50 mph, you don’t think anything about it,” he told Wired Magazine. “But on a bicycle, it feels way too fast.” Recently he started selling the bikes on eBay.
In addition to strapping jets onto bikes, Maddox who was an avid skydiver for 20 years decided to strap a jet to his chest and make himself into a human missile. He discovered that turbine jet engines are expensive but pulse jets are cheap and simple so Maddox set to work building one. “All I started with was a schematic out of an encyclopedia,” he says. The engines are basically a long tube with a fuel pump, a spark plug and a reed valve. Air and fuel are mixed at the front and ignited in a process that repeats – or “pulses” – about 70 times a second.
He started refining his pulse jet engines, which he fashions from aluminum and stainless steel in his workshop. He’s sold about 50 of them. The smallest are used to power model airplanes. The largest – two monsters producing 500 pounds of thrust apiece – have joined the beastly nitro-methane engine in Wally Larson’s Top Gun Groundfighter show car. (Blog.wired.com)