(CBS NEWS) LOS ANGELES - Motorcycle enthusiasts called "stunters" defy both gravity and the law as they perform high-speed tricks on America's freeways.
A 33-year-old stunter who goes by the biker name Krash is a member of the Elite Bikerz Club in Southern California. Many of his daredevil tricks are posted on YouTube. He knows some of hits stunts are illegal, but he does them anyway.
"I feel almost like I guess what you call every other middle-aged man. You know, we're 9-to-5 during the week. I'm married. I have three kids. And this is my rush," Krash said.
In California, the number of motorcyclists on the road has gone up 53 percent in the last 10 years -- and most of them are law-abiding, officials say. But large groups of riders -- sometimes hundreds at a time -- can pose a safety threat to other highway drivers.
In New York City last month, police say anin front of his wife and young daughter during a motorcycle rally known as the annual Hollywood Block Party.
California Highway Patrol Officer Ming-Yang Hsu says biker groups can cause a lot of headaches for other motorists -- and put them in danger, too.
"When we have groups of motorcyclists blocking the freeway to slow it down so that they have room to perform tricks, that's when we have impeding issues," he said. "It's illegal to be doing the tricks, popping a wheelie, spinning around, things like that. It is reckless driving."
Ivan Morales, president of Elite Bikerz of downtown LA, stresses that his group is a club, not a gang. He says the club frowns upon any member doing illegal stunts, but said if other bikers choose to do it, "We can't stop them."
Krash says he doesn't feel like a lawbreaker. "You've got to be a smart rider," he said.
But doing tricks like speeding along on just one wheel on the freeway doesn't seem too smart, or safe.
"I believe it can be controlled," said Krash.
Asked what would make him stop, he replied: "I believe really nothing."
A ticket for reckless driving costs at least $145, but that's not enough to deter these dangerous thrill seekers.