This is not your father's pogo stick. Unlike the spring-driven toys many children use to bounce up and down, an extreme pogo stick can propel you over 8 feet into the air, leaving plenty of time for airborne spins, flips, and other tricks. How does it work?

"Tricks on pogo sticks have been around for a while," says Fred Grzybowski, a leading pogo athlete and an organizer of the extreme pogo movement. After all, pogo sticks were first developed and marketed as toys in 1918 – but the original tricks performed on them were hardly extreme. Traditional toy pogo sticks rely on steel springs to create bounce. When a rider lands on the ground, her weight compresses the spring, and as she pulls back up, the compressed spring recoils, helping drive her back into the air. This basic technology can barely propel riders a foot into the air. Even on adult-sized versions of the spring-based sticks, pogo riders had always had to skip daring tricks in favor of more technical performance pieces, such as balancing on a foot pedal.

With the advent of the internet, though, pogo riders could share these technical abilities, performing and taping stunts that they then posted online. Several pogo sites sprang up, providing forums and a community for sharing tricks. The smaller sites were eventually incorporated into the dominant Xpogo, the heart of the extreme pogo community. Xpogo's organizers also established the yearly competition Pogopalooza, which takes place in a different city every year, and the performance team The Pogo Dudes, who have appeared on a variety of American talk shows.

At the same time as the internet was bringing pogo enthusiasts together, researchers were ditching the traditional, easily breakable steel springs in favor of more powerful bounce impetuses, creating high-performance pogo sticks. Today's pogo sticks can propel their riders up to eight or nine feet high, providing air time for a variety of tricks and flips.

High-performance pogo sticks

"There's a blank canvas between the handlebar and the foot pegs to create bounce," explains Nick Ryan, a member of the Xpogo team and one of the organizers of Pogopalooza. Modern pogo manufacturers have found several new ways to fill in that canvas.

For example, one of today's most popular extreme pogo sticks, called the Vurtego, uses air — compressed air, to be precise. According to the official website,

"The body of the Vurtego pogo stick is a thermoplastic cylinder which is also the compression chamber for the air spring. It houses a piston and seal that are attached to a stainless steel slider shaft that extends out of the bottom of the pogo stick. A fill valve in the top of the stick allows the rider to add air to the cylinder to whatever pressure is desired. The higher the air pressure, the stiffer the spring."

Before mounting a Vurtego, riders fill it up to the desired pressure with a bike pump. Then, it can propel them over seven feet up into the air. Extreme pogo athletes use this height to leap over bars in high jump competitions, and to do flips and other tricks. But air isn't the only way of reaching new heights.

Grzybowski, for one, prefers the Flybar. "It has heavy-duty elastomers inside," he says. "Elastomers are big thick rubber bands. In my pogo stick I have up to 10 of them." When Grzybowski hits the ground on his Flybar, he stretches out the elastomers in the body of the pogo stick. Then, as he pulls up, the bands recoil, providing thrust to help him jump high into the air.

The elastomers provide a more gradual stretch than the abrupt recoil of steel springs, providing a smoother ride." According to Grzybowski. "It feels more like a trampoline." The Flybar's soft bounce has allowed it to retain some popularity among extreme pogo jumpers despite the fact that it breaks down more easily than the Vurtego: Riders are more likely to accidentally snap a rubber band than to somehow break down a column of compressed air.

The bounce of a pogo stick doesn't have to come from the inside. An external fiberglass bow drives the BowGo, developed by Ben Brown of Carnegie Mellon University's Robotics Institute since the late 1990s.

The bow-driven propulsion was originally used to create a bow-leg for a light robot, before Brown decided to scale it up and use it to power a pogo stick. As he says, "It just happened that we were building springy robot legs that were very efficient, so I decided to build a pogo stick using the same spring technology." In a BowGo, the bow replaces the traditional pogo's steel spring. When the pogo stick is motionless, the bow looks like a broad ribbon hanging parallel to the shaft. Brown explains, "The top end of the bow attaches to the housing up near where the handles are, and the bottom end attaches to the plunger that goes in and out of the housing." When a rider hits the ground, the plunger at the bottom goes into the shaft housing and the external bow flexes into a C. "As it bends, it stores elastic energy, and when it takes off, that spring energy is converted into vertical velocity, which sends the rider into the air."

Brown has handed over some of his BowGo prototypes to extreme pogo athlete Curt Markwardt. "He tries them out and sees what he can do with them," Brown says. Riding on a BowGo, Markwardt set a pogo high-jump world record in 2009, bouncing eight feet and 7 inches high. (That record has since been broken, and now stands at 9.5 feet.)

With input from Markwardt, Brown is continuing to develop his Bowgo prototypes in his spare time. Meanwhile, scooter manufacturer Razor has licensed the rights to the Bowgo design from Carnegie Mellon, creating a child's version called the BoGo, which cannot bounce as high as Brown's high-performance version. For the time being, the bow-driven pogo stick remains less common than the Vurtego and Flybar. But Brown doesn't mind - he's also busy using that same bow-leg technology for other purposes, such as the wall-climbing ParkourBot.

Making pogo extreme

"Extreme pogo sticks definitely fueled [the sport] to make it where it is today. There were tricks before that, but I don't know where my life would be if we didn't have high-performance pogo sticks," Grzybowski says. The heights that modern pogo sticks can reach are important for helping the extreme pogo movement overcome the idea that these sticks are just lame toys.

"[Extreme pogo] used to be a joke," says Ryan. "We used to be on the defense a lot." To overcome the stigma of pogo as toy, the extreme pogo movement has had to market itself. As Ryan explains, "We slowly built it through yearly touch points… At the first Pogopalooza there were six people in a parking lot in Nebraska." And the most recent Pogopalooza 8 included participants from across the United States, Canada, England, and Australia. In 2013, organizers hope to hold the tenth Pogopalooza in Times Square.

In addition to competitions, the movement's organizers aim to increase its public profile with performances from teams like the Pogo Dudes. Pogo athletes have performed in online videos, parades, busking, and on a variety of talk shows. Despite the increased publicity, pogo remains a fringe sport. "We want to make it a staple of the extreme sport world – but it's an uphill battle," says Ryan.

And in this battle, high-performing pogo sticks are perhaps the movement's greatest weapon, helping extreme pogo come into its own.