They make some of the most extreme stunts look like child's play.
"I've been riding my bike since I was like 10 years old," said Dew Tour rider Mike Spinner. "I loved it, I've been doing team sports all my life, when I got a little older, I said, 'Man, I just want to ride!'"
Almost 200 of the best BMX riders from all over the world will kick off the Dew Tour in Chicago, including last year's champ, one of the biggest names in the sport.
"I never plan to, to be honest, win these things," said Dave Mirra. "It's fun to come out and ride, do my best, but there's are so many good guys, and I mean, if you win one, it's awesome... You're going to see pretty much all the cutting-edge stuff her at Dew Tour."
How does anyone learn how to do this?
"There's pretty much training facilities," said Spinner. "Soft, padded landings. So, for instance, you try these crazy tricks in the foam pit, just like gymnasts do, and from there you bring it over to the resi, which is a soft, padded landing and you get it super-dialed, and when it's time, it's go time."
Mirra says the only time he might be scared is before doing a stunt - but not while he is in the middle of one.
"When you're sitting there, you think about things, and even like today's practice," said Mirra. "I have to scare myself a few times, just go for it, see what happens."