In 2000, Brown and another Carnegie Mellon engineer, Illah Nourbakhsh, built their first BowGo prototype. Instead of piano wire, they bolted a strip of structural-grade fiberglass to the outside of the pogo’s aluminum frame. They fastened the top of the fiberglass strip near the handlebars and the bottom to the plunger. When a rider lands and the plunger shuttles through the frame, the strip flexes and then abruptly straightens, reversing the plunger and launching the rider skyward with as much as 1,200 pounds of force. Ounce for ounce, they discovered, this fiberglass “leaf spring” stored as much as five times the elastic energy as a conventional steel coil.
After a couple of years of field testing in his backyard and on campus greens, Brown pogoed over a bar set at 38 inches. “A couple of times, the foot slipped out and I was unconscious for a bit,” Brown recalled. “I remember some guy standing over me and saying, ‘Do you know your name?’”
It became clear that Brown, a grandfather of four, needed a younger test pilot. He shipped a prototype to Curt Markwardt, a Southern California video game tester who learned his first tricks on a $5 pogo stick that a friend had bought as a joke at a toy store’s going-out-of-business sale.
Within months Markwardt had somersaulted on the BowGo over his car and cleared a bar set at 8 feet 7 inches, a record. When he’d first told friends about his passion for pogo, “people would kind of chuckle,” Markwardt told me. “They think of little kids bopping up and down and not doing anything.” But when “they see you jump six feet in the air and you do a flip, holy cow...it turns into instant awesome.”
Brown is eager for Razor to release an adult version of his stick, but so far, only the children’s model is for sale. The bow leg, meanwhile, is still kicking. In 2008, Brown and a team of colleagues won a grant from the National Science Foundation to develop the technology into a lightweight “parkour bot” that climbs by leaping between parallel walls.
When Bruce Spencer retired after 28 years as a firefighter in Huntington Beach, California, he imagined a simpler life. A husky man with a broad brow and ruggedly handsome features, he dreamed of flying his two-passenger Cessna to Idaho and Colorado and scouting the wilderness for a patch of earth to build a cabin and live out his years with his wife, Patti, in quiet.
A few months after leaving the department, though, Spencer hosted a family party. His nephew Josh Spencer had built a prototype adult-size pogo stick, stuffing a 33-inch steel spring into an aluminum tube. But the weight of all that metal made the stick unwieldy. Josh was venting about it at the party, and Bruce Spencer’s son Brian went to his dad for advice.
“Brian comes in and says, ‘Hey Dad, if you ever made a big pogo stick for adults, how would you do it?’” Bruce Spencer recalled.
Before joining the fire department, Spencer had earned a degree in aerospace engineering and worked at Northrop on the design team for a lightweight fighter jet that would become the F-18. His son’s question lit up a dormant part of his brain.
Spencer penciled a diagram in the margins of a newspaper. “Make an air spring,” he told his son, “because it would be very light.” With that, he considered himself rid of the matter. “Just fun and games,” he told me, with the tone of a man recalling a spell of youthful naiveté.