An immense, multi-colored ocean of 3,500 bicyclists joined hometown hero Levi Leipheimer Saturday in a historic communal Sonoma County ride, the King Ridge GranFondo.

"I want everyone to be safe but have fun," Leipheimer told the asssembled riders, crowded shoulder to shoulder as they readied to leave Finley Community Park for routes of up to 103 miles from Santa Rosa to the coast and back.

"Sometimes you go straight up and sometimes you go straight down," said the internationally renowned racer who lives in Santa Rosa and who organized the county's largest-ever group ride. "It's very organic."

And, as many riders experienced it, a sweat-drenching, leg-cramping, ego-threatening confrontation with twisting coastal hillsides.

"Oh, God. I'm so blasted," Sebastopol cyclist Rick Pepper said, breathing hard, after six hours of pedaling that took him from Santa Rosa to the Sonoma coast via King's Ridge Road from Cazadero, up a total 6,500 vertical feet. "But it was good."

Pepper was one of the 1,500 bicyclists who signed up for the most grueling, 103-mile route that Leipheimer, a three-time Tour of California winner and third-place Tour de France contender, uses as a training run.

After taking riders into Occidental via Graton Road, the course included Cazadero and Bohemian Highways, King Ridge Road, Highway 1 and Coleman Valley Road.

Those choosing to ride shorter courses Saturday covering 65 miles - the MedioFondo - and 35 miles - the PiccoloFondo - faced their own challenges as they pushed their way up a long ascent into Occidental or rounded southbound Highway 1 from Jenner onto Coleman Valley Road north of Bodega Bay.

Police and event organizers said the ride went smoothly, especially given the thousands of riders along narrow country roads where riders even had to share space with farm tractors along busy city and rural roadways where law enforcement officers controlled key intersections.

Two riders were taken to the hospital for treatment and one was treated for abrasions, according to a spokesman for the ride. He would not give further details on the injuries.

The ride into Occidental forced some riders to walk at various points, while other simply remarked on its length.

"It's 1.8 miles," observed Don Blodger, 57, of Sacramento. "But who's counting?"

It was the uphill climb from the coast back inland on Coleman Valley Road that garnered the most verbal abuse from Gran and MedioFondo participants.

"Every time you get up a hill you say, &‘Oooh, I'm glad that's over,' and then you go around a curve and there's another one," San Francisco's Jacob Berkman said, his arm's aching from the buffeting winds at the upper reaches of the GranFondo.

Gran Fondo means "big ride" in Italian and is the name given to long-distance, mass-participation cycling events — not races — that are immensely popular in Italy.

The ride got underway as Leipheimer and his wife, Odessa Gunn, rode across the starting line, though other participants had to walk their bikes across the line because of the press of the crowd.

A few - apparently feeling unity with the Bay to Breakers and other foot races - donned zany Viking headwear and velvet crowns along with their helmets.

Organizers said 65 percent of the sold-out event's profits will go to efforts to secure a place for Santa Rosa in the 2010 Amgen Tour of California cycling race. The remaining 35 percent will go to Forget Me Not Farm, a nonprofit group backed by Gunn that provides therapy for troubled children on the grounds of the Humane Society & SPCA of Sonoma County.

Riders who came from across the U.S. and abroad paid as much as $115 to participate.

Santa Rosa resident Hugh Alberson, 56, like several others, said he rode Coleman Valley Road in 100-degree heat last weekend as a practice run, "which was kind of bad, because I was thinking, &‘Do I really want to do that again?' "

Simply put: "Coleman Valley Road is a beeetch," said Alberson.

Conchita Robson of San Francisco, the self-described "girlfriend who got stuck doing this ride" along with boyfriend Chris Toshok, said after finishing 65 miles that Coleman Valley Road was "really hard."

While she walked her bike up some of it, "there was someone riding, holding onto a truck, so that made me feel better about walking."

Participants, many of them fans of both Leipheimer and the Tour of California, said they were overjoyed to have a chance to support both.

Others said they'd read or heard about Leipheimer's training ground and appreciated a chance to try it out, see Sonoma County and test their own mettle.

And then, Sacramento resident Blodger, said with a smirk, there was "the opportunity to maybe say to Levi, "on your left!' "