The Republicans had one thing right when, last September, New Jersey Gov. Chris Christie called the explosion of climbing walls on college campuses an “epidemic.”

Climbing has finally reached that critical point where the massive influx of new participants is not only eclipsing the old guard but is fundamentally changing what it means to be a climber.

We’ve crested what bestselling author and speaker Malcolm Gladwell would call a “tipping point,” where rapid change is now unstoppable.

“We are being taken over by the gym generation,” said Jason Haas, owner of Fixed Pin Publishing in Boulder. We, being the 30-something and older climbers who learned to climb outside.

Today, most new “rock” climbers start indoors on plastic holds. Gyms are the ideal place for new climbers to learn without the hazards and inconvenient variables of climbing outside. Personally, I’m thrilled to see climbing thrive.

But it’s not without growing pains.

“Right now there’s a battle over what defines a climber,” said Celin Serbo, a climber of 25 years from Lafayette. Many gym rats, for example, will never climb real rocks.

Over time, climbing has become less lifestyle and more sport; less rebellion, more discipline; less dirtbag, more athlete. The drug-taking, dumpster-diving rebels of yesteryear now monitor protein intake and perform weighted fingertip pull-ups in the gym.

“The original dirtbag doesn’t exist anymore,” said Lynn Hill, of Boulder, who began dirtbagging in Yosemite in the 1970s. “I was a kid who wanted to climb as much as possible and having a job got in the way of that.” She collected aluminum cans for cash and rationed her food.

Incidentally, Hill quickly became one of the best, most well-rounded rock climbers in the world. Today, 41 years into her climbing career, she seems to love it as much as ever.

“It’s just a different culture now,” she said. “The people who are getting into climbing are not dirtbags. They’re professionals, they’re hard workers, they’re high achievers.”

James Lucas, associate editor at Climbing Magazine in Boulder, agreed.

“People don’t need to dirtbag anymore,” he said. “There’s no need to sit out in the middle of the desert waiting for a climbing partner when you can Facebook message a friend and hit Movement for an evening climbing session.”

Before taking the job at Climbing Magazine earlier this year, Lucas was featured in a short film as “The Last Dirtbag,” having devoted himself to climbing — and to life on the road — for more than 10 years.

“I think the obsessive, niche culture has faded,” said Maury Birdwell, an attorney in Boulder and climber of 16 years. “As Men’s Journal put it, climbing is ‘the new CrossFit.’ Go into any modern, metro area gym and you’ll see it: the climbing gym is about cool fitness while sporting the right style.”

Growing pains, indeed.

And they’re more than skin-deep.

“Being a climber used to mean knowing how to build an anchor and how to rappel,” said Serbo. “It meant functioning in the outdoors, camping, route-finding and following a topo map. It’s these things the gym culture of climbers is clueless about.”

When gym-bred climbers do venture outdoors it’s crucial they hire a guide or learn from a mentor — the old-school way — lest climbing know-how once considered essential be forgotten.

“Technical proficiency has stagnated or perhaps even lowered,” suggested Lucas, regarding today’s average rock jock. “Climbers used to travel to Patagonia or Yosemite with a much stronger skill set for self-rescue than they do now.”

As Roy Leggett, a local firefighter and climber of 24 years put it: “The new climbers tend to lack diversity in their skill set. They often skip the school of hard knocks of learning from experience and mistakes.”

However the young guns choose to climb, they’re the ones who will soon define our sport. And through this epidemic, it’s up to climbers of my generation to teach, support and be humble enough to learn from a new kind of climber.

After all, they’re doing something right: They climb a lot harder than we do.

Contact Chris Weidner at cweidner8@gmail.com