P.J. Dailey won this July 2011 race at Schaeffer Farms at a Cranky Monkey Mountain Bike Race in Germantown. (Courtesy Pete Dailey/Swim Bike Run Photography)

It wasn’t until after the motorcycle crash in 2009 and a lifetime of running and jogging that Pete Dailey got on a mountain bike.

“My son was interested in mountain biking; I bought a bike to go riding with him,” Dailey said in a recent interview.

He was 47 years old, and he hadn’t ridden a bike since he was 16, he said. But he still remembers the day he caught the mountain biking bug as an adult.

One day that summer, he rode through Lake Fairfax Park, the air hot and dusty, and he struggled up a hill.

“I was truly questioning what I was doing and why I would work this hard,” he said.

“After putting my foot down a few times, I realized the more I pedaled, the more I was able to get up and over obstacles that were so forbidding at first glance,” he said.

Then he crested the hill and came zooming down.

“It was a relief, it reminded me of skiing. As soon as I got to the bottom I blocked out all the negative thoughts of the climb before and just wanted to climb back up because coming down was so much fun,” he said.

Dailey and his son, P.J., started riding near Lake Fairfax. Dailey works as a civil engineer for the Fairfax County public schools, where his son is an employee, as well.

Like several other area mountain bikers, they both enjoy biking the trails at Fountainhead Regional Park, where a mountain biking advocacy group called the Mid-Atlantic Off-Road Enthusiasts (MORE) will complete a new, upgraded, $150,000 trail later this year.

“It’s funny to look back – it’s been so long since I started thinking ‘This is something I’m passionate about,’” said P.J.

In that, he’s got lots of company — and lots of trails to traverse.

There are 450 miles of trails between Delaware and Northern Virginia, said Dave Ferraro, president of MORE, which this year put over half a million dollars into trail maintenance as well as 7,000 volunteer hours maintaining the trails he and the other members of MORE zip around on.

“Mountain biking [is] a great way to get out into the woods quickly and quietly on a really simple, amazing machine,” he said.

Kyle Bondo, spokesman for the Potomac Velo Club, an area cycling club, said the area’s trails are also in­cred­ibly diverse. “You could learn every technical skill, and there’s a trail that would need those skills,” he said.

According to USA Cycling Spokesman Bill Kellick, the number of “licensees,” which includes riders, coaches, mechanics and others involved in races around the country, has grown from 42,724 in 2002 to 74,516 licensees in 2012.

The group has nearly 60,000 active members currently, and the number of cycling clubs has swelled from 1438 to 2812, according to USA Cycling data.

“With five different disciplines, there’s something for everyone in there,” Kellick said, referring to road, BMX, mountain, track and cyclo-cross biking.

“I found the racing scene to be very low pressure and fun,” said Dailey.

The other racers welcomed him in, he said. And he noticed something else, he said: “I was seeing a huge rise in middle aged men getting into cycling clubs. Instead of buying fancy sports car, they were buying a fancy bicycle.”

As with learning to mountain bike, the races he began entering were an initial struggle: Dailey couldn’t finish his first three.

“Neither of us did well in beginning … I more had the technical skills, but I didn’t have any endurance, the ability to just keep going,” said P.J., now 22.

“When we rode together, I was the rabbit, he was the fox chasing the rabbit,” P.J. said.

Dailey was soon completing races, then creeping to the middle of the pack, finishing with other members of his age group.

Many of the racers were around his age, he said, and still having successes in races, he said.

That led him to getting a coach and getting serious. He qualified for the national championships as an amateur that year. Now 51, Dailey regularly “podiums” or finishes in the top five for his age group at races around the country. He doesn’t ever expect to go pro; but he is moving up to the next skill level.

“At my age bracket, I doubt I would go pro… but I can see my son working his way to a professional team,” Dailey said.

He and P.J. like to challenge each other over obstacles when they’re out riding, he said. “Which is good and bad,” he said. “We get hurt, but we get better at navigating obstacles.”

Just days before Christmas last year, P.J. went for a ride with his father.

“Thirty seconds into it, I’m laying on the ground wondering why does it hurt so bad,” P.J. said.

He’d broken his leg near the knee. The crash sidelined him, wiping out his endurance, he said.

He got back on his bike about 10 weeks later, he said, but it took four to five months to fully recover from the crash.

Now, there’s still the question as to who’s faster. “That’s a subject of great debate – but I have more endurance at this juncture – so I’m currently faster,” Dailey said. “But I know it’s not for long.”

In a separate interview, P.J. said about the same.

“As of right now, he just has a year on me…. But I can see myself getting faster right now, so I know I’ll outdo him. It’s just slow and steady…”