CARRABASSETT VALLEY – Live long enough and eventually you realize there are some sports you’re destined never to understand.

Take Acapulcan cliff diving.

Most anyone can imgagine how back 100 years ago some poor Mexican peasant being chased by the Federales might have decided to take his chances by going over the cliff rather than be trampled.

What I’ve never been able to get past is the idea that immediately upon surfacing and finding himself alive, the first cliff diver thought, `Aye caramba, that was great. I think I’ll do it again and get my buddies to try it, too.’

Ditto ski jumping. I have no trouble envisioning the first ski jumper. He had to be some Scandinavian who, while trying to outrun an avalanche, happened to hit a big bump. He went airborne for a couple of hundred feet then miraculously landed on his skis, no doubt drawing thunderous applause from fellow villagers moments before they were all buried.

Fine. But that doesn’t explain why other Scandinavians subsequently built huge ramps to try and recreate the experience.

I’m adding mountain bike racing to my list of incomprehensible sports. Specifically, the slalom.

After spending Saturday at Sugarloaf USA watching more than 800 mountain bikers from around the country careen down the mountain in something called the Samuel Adams Widowmaker Challenge, I came to the conclusion I am never going to understand this sport.

Here’s what I mean:

While walking into the event I had to climb a steep set of stairs made out of railroad ties. As I hit the first step I looked up to see some kid dressed in skin-tight fluorescent green and pink Lycra. Over the Lycra he had on orange plastic pads that protected his knees, shins, elbows and shoulders. On his head he wore a blue plastic helmet. The kid looked like one of those Ninja turtles.

Ninja was on his mountain bike, which appeared to be a cross between my old stingray and my old 10-speed – fat, knobby tires and low, curved handlebars with handbrakes. I later learned some of these mountain bikes cost $3000, a fact that wouldn’t exactly aid in recruiting me to the sport.

I got my first inkling this was all going to be beyond me when this kid, without even blinking, rode his bike right… down… the… stairs.

Who invented this, anyway, I wondered, Beavis or Butthead?

Judging by the competitors, it seems mountain biking is a Generation X “thang.” You know. Young. Alternative. Extreme.

I figured this out when the first sign I saw on a sponsor tent read: `Hydrate or Die.’ There were catchy slogans on many of the bikers’ Lycra jerseys as well. Like, `Hell Bent Trail Hogs.’

“It’s an extreme sport, definitely,” agreed Troy Fenderson of Concord, N.H., who won Saturday’s expert pro elite men’s downhill competition.

I was not talking to Troy because he won the downhill, an event which offers the improbable image of people peddling like crazy down a 2.3-mile mountain course. I was talking to Troy because of what happened to him in the slalom.

You remember the slalom. Two competitors race down the hill on a parallel course, negotiating tight turns marked by flexible gates. Only, in mountain biking they throw in a twist. In between every third set of gatebiking they throw in a twist. In between every third set of gates, they put a jump.

During his first run in the heats, Fenderson hit the third jump a little too fast and, well, let him tell it.

“I didn’t set up in time for the jump. What happens is you’re not sitting back far enough, so it sends you forward,” he explained.

Forward. Yes, that’s where Fenderson went. After soaring forward through the air he landed on his front tire, which sent him flipping forward over the handlebars. He landed on his shoulders, and somersaulted forward down the mountain.

The technical term for this is “taking a digger.” In mountain biker-speak, someone who takes a digger invariably becomes a “yard sale.” Get it? Belongings scattered all over the yard.

Fenderson, who works as, of all things, a safety engineer when he’s not traveling the pro biker circuit, has taken his share of diggers since giving up motorcycle racing for mountain bikes a few years ago.

“I broke my collar bone at Mount Snow during the World Cup last month,” said the 25-year-old, whose smile betrayed a broken front tooth. “It was a flip just like this one.”

And the tooth, he was asked?

“That happened last week in a cross country race. The guy in front of me hit a tree branch and it snapped back…”

You should know Fenderson did not become much of a yard sale after taking his digger. He came out of his somersault by popping neatly into a standing position. The 1,000 or so spectators who had gasped at his flip, roared in appreciation. Fenderson took a bow.

“You’ve got to work the crowd in this sport,” he said.

Right. I guess I’m going to need more work.