The inventors of the bicycle meant for it to be used as a means of transportation. Children, Lance Armstrong and environmentally conscious commuters will be eternally grateful. We’re pretty sure that the two-wheeled innovators never envisioned their creation flying upside down, 25 feet above the ground after launching from a halfpipe or dirt jump.

Since the birth of BMX in the early 1970s, riders inspired by the motocross circuits have been pushing the envelope on how hard they can race and ride their bikes. It didn’t take long for these adrenaline junkies to begin searching out new terrain, sicker tricks and higher airs. Eventually, the sport was split into five categories: Freestyle Vert, Freestyle Street/Park, Freestyle Dirt, Freestyle Flatland and Racing.

“It’s evolved so much over the 26 years I have been doing it,” says veteran BMXer and 2006 X Games gold medalist Kevin Robinson. “I watched it go from the California surfer-type image, to underground—where it just died out—to the birth of the X Games in 1995, to where we are today.”

One of the most obvious changes over the years has been the level of difficulty of the tricks. Gone are the simple Endos, Cherrypickers and Bunnyhops. In their place are 540 Caballeros, Icepick Grinds and Double Flairs, which Robinson invented—it’s two-and-a-half flips while soaring over a vert ramp.

“It’s been cool just to watch the progression of how much tricks have changed, how much they have evolved,” Robinson says. “[It’s impressive] how many things that you never thought were possible are being done now. It is just amazing.”

With momentum growing and BMX reaching a global fan base—it was an Olympic event for the first time at the 2008 Summer Games in Beijing—the sky is literally the limit for this high-flying action sport.