A 'bicycle' built for six -- and speeds of 60 and up
Boston — They may look neat upon the seat of a "bicycle" built for six . . . but will they top 62.93 miles per hour? Some 30-plus bicycling enthusiasts with a high-speed gleam in their eyes would answer with an unequivocal "yes." They have begun to assemble what they hope will be the fastest human-powered vehicle (HPV) in the world.
Pooling the intellectual and physical resources available at Massachusetts Institute of Technology, a team of students and faculty advisers has set its sights on the Aspro Clear Speed Challenge, an annual event to be held this year in Brighton, England, on Sept. 5.
In the next two months they will construct a 42-foot-long, 32-inch-high, seven- wheeled cycle designed to break the May 1980 record of 62.93 m.p.h. set at California's Ontario Motor Speedway.
Group Velocity, as they have dubbed themselves, will enter "the largest HPV ever to compete for the record," says Howard Rosenberg, project manager.
One of the key links in the chain to success lies in the number of cyclists the group will put astride the vehicle. The Vector, the HPV that holds the speed record, was powered by three riders. But, figure MIT builders, why stop at three? Why not use six cyclists?
They reason that upping the number of riders means more power. But that concept will only propel an HPV so fast. There is a point where the power advantage from more riders is swallowed up by their additional weight.
Aerodynamically, though, there is no reason not to add riders.All vehicles have to overcome wind resistance. If two HPVs have the same frontal area, the resistance will be virtually the same for both of them. So the drag for a three-rider vehicle, if the cyclists are in single file, will be the same as that of a six-rider vehicle.
"Europeans have known the value of conquering wind resistance for decades," says Peter Boor, co-president of the International Human Powered Vehicle Association. But in 1973, it was the "rediscovery of the importance of streamlining" which sent cycling aficionados pedaling off in pursuit of speed records, says Mr. Boor.
Dr. Chester Kyle, a professor of engineering at California State University at Long Beach, conducted experiments that revealed that when a bicycle is pedaled at 25 m.p.h., 90 percent of the resistance is due to atmospheric drag. Enclose a bicycle in an airfoil shell and atmospheric drag is cut by as much as 60 percent.
So Dr. Kyle put a cyclist on a bicycle enclosed in a streamlining cocoon and promptly broke a number of speed records. Three years later, he helped form the International Human Powered Vehicle Association (IHPVA) to sanction and recognize HPV speed records. And, the competition began in earnest.
Group Velocity entered the fray at the urging of MIT undergraduate Bruno Mombrinie. He went to the annual IHPVA championships in May to see what was being done with recumbent cycles -- those ridden in a reclining position. He returned with visions of a record- shattering cycle.
Now, two months after Mr. Mombrinie's return, members of Group Velocity are confident the current HPV record is within their grasp.
"We're aiming for 70 m.p.h. We have the talent to do it and our computer studies have shown that it is quite possible," says Mr. Rosenberg.
As one would expect of a premier engineering school, due consideration is being given to the brawn-power needed for the project. A team of high-caliber cyclists is going through a rigorous training program. The best cyclists will be selected through a specially designed dynamometer test. When their vehicle is completed, they will spend a month getting crucial on-the-seat experience.
"Eric Heiden, Olympic speed skating gold medalist, and John Howard, US cycling champion, showed up at the competition in May without any training on this type of vehicle. They crashed before they reached record- setting speeds. But each time they got on their cycle they went faster. In other words, unfamiliarity and lack of practice may have kept them from setting a record. We don't intend to make the same mistake," Rosenberg explains.
The university has staked $5,000 on the project. However, the cyclists won't get past the first pylon unless they can find in the next month sponsors willing to bankroll them for an additional $34,000 to $48,000.
The technology used in propelling the Group Velocity cycle, and others like it, is just beginning to reach the marketplace. For instance, recumbent cycles now are being sold by small independent entrepreneurs. These cycles, built for a low profile and a reclining rider, will go faster than a conventional bicycle using the same amount of effort. And the big bicycle-component manufacturers have begun to sponsor entrants in the IHPVA- sanctioned races. But support from bicycle manufacturers themselves is lacking. There is interest, but because of the limited practical use of cycles built for speed only "it is a low-level interest," Boor explains.