Like most of the race’s other kinetic sculptures, Wenda would run on pedal power, like a bicycle does. Bicycle wheels are great for multiplying speed (see Speed Boost). When pedaling, a person applies force to turn the axle at the center of a wheel. The spokes of the wheel work like levers to amplify the force on the wheel’s rim. That causes the outside of the wheel to turn faster. But skinny bicycle wheels can’t withstand the lateral, or sideways, forces that result from turning a corner with a large, four-wheeled vehicle like Wenda.
“When you ride a standard bicycle, you lean into a turn so it doesn’t put really heavy lateral loads on the wheels,” says Steve McHaney. He’s a kinetic racer and civil engineer at GHD, a company in California. “But when you use that same kind of wheel on a four-wheel machine and go around a corner, the wheel can just fold right under you.” To avoid having their wheels “taco,” the Jemicy students chose ones that were wide and sturdy.