Tinkerer Hopes 15th-Century Dream Will Go Into the Record Book : Visionary Monocycle Rolls Into Reality

Dave Moore has been chasing one of Leonardo da Vinci’s dreams for six years--and he is finally ready to roll.

Moore, a 37-year-old Rosemead resident, has built a rideable monocycle, a machine sketched by Da Vinci in the late 15th Century--a feat that may garner Moore his second listing in the Guinness Book of World Records.

“Studying literature on old bicycles, I would come across these fantasy drawings and always wondered if anybody ever made one that was functional,” Moore said. “There are these fanciful drawings and a couple of recorded attempts, but no record of anybody actually riding one, so I wondered how far it went. I’ve been mulling over the idea for two years; the main thing I’ve done is to take it a step further than anyone else.”

Looking for all the world like a cartoon bicycle gone awry, the monocycle is not to be confused with the more common unicycle. A monocycle rider sits on a seat inside the single wheel; the design has to permit the driver, pedals and seat to remain upright while the outer wheel rotates. It is far more difficult to keep balanced and fight gravity on a monocycle.

Although the monocycle is generally regarded as an original flight of Da Vinci’s fancy, its origin is open to question. UCLA Prof. Carlo Pedretti, perhaps the world’s foremost expert on Da Vinci, says the famed Italian artist-scientist only sketched a man inside a wheel being pushed by another man.

Like many ideas attributed to Da Vinci, the monocycle was so advanced for its time that it was not until the second half of the 19th Century that inventors tried to make working models. A number of monocycle patents were taken out in 1869; one machine built by Allen Green and Elisha Dyer of Rhode Island was recorded as “an improvement in velocipedes (monocycles)” but reportedly crashed badly on its trial run and proved to be unsatisfactory.

The French and English tried their hands at it. One English writer in an 1869 article titled “The Velocipede: Its Past, Its Present & Its Future” mocked the concept: “Of course, we have never seen one of these monocycles at work, and as we have, from our youth up, been taught to look upon the human frame as designed for higher ends than being broken on a wheel, we have never increased our coachmaker’s bill by ordering one.”

Moore, who repairs wrecked motorcycles for a living, said his machine “took about three months of spare-time work and about four weekends of testing to get to the state where it’s rideable,” a feat that might qualify it for a Guinness entry.

It cost about $100 for materials--steel tubing, hard rubber for the wheel, salvaged bicycle parts--and Moore says it “could have been built 100 years ago. But even on the best dirt roads they had back then, it would have been nearly impossible to ride it.”

Not that it’s very easy to ride now. “Starting off could be a problem until you hit stability speed, about 10 m.p.h.,” laughs Moore, who has taken a few spills getting the hang of it. “You need a second person to help hold you up until you get going.

“The first ride wasn’t successful because we went down a narrow road . . . and couldn’t turn around. The second ride was in a parking lot on New Year’s Day, the first time we had enough success that you could call it a rideable monocycle. The first couple of weekends we were just stumbling, changing things.

“With more experience, we’ve gotten better at riding it--the longest ride is 10 minutes at about 13 m.p.h., timed between two light posts. The machine weighs about 100 pounds--you tend to get winded.”

Solving the technical problems proved surprisingly easy for Moore, who has been a mechanical whiz for as long as he can remember. The monocycle “is the first model; I had to change the design in midstream. The biggest thing was to keep lowering the seat--the lower the center of gravity of the rider, the better everything worked. Sitting up too high, you would do a somersault too easily.”

Moore, a stocky six-footer who sometimes outfits himself like a 19th-Century gentleman bicyclist, tailored the machine to himself. “The wheel is the smallest size that a 6-foot-tall person could fit into when you start figuring out the crank and pedal position, etc. I made some rough sketches, and then a metal ‘loop’ that I positioned everything in. The bike now is 7 feet outside diameter, 6 feet inside, but a smaller person could ride it by putting the seat forward.”

Moore’s interest in historical bicycles started at work. “People were coming into the shop asking us to build 3-foot-long spokes for their high-wheel bikes, and I got interested and wanted to learn how to ride one,” Moore said. “But you can’t ask a guy to let you learn on his antique machine, so I ended up making a reproduction--and that one led to nine more over a period of five years.”

One of those early machines earned Moore his first slice of fame in the Guinness Book of World Records. He is the proud builder of “Large Marge,” a unicycle with a 66-inch wheel, listed as the largest useable unicycle.