For Josh Horowitz, the light went on when he was 13.
His father took him to the Manayunk Wall to watch the 1988 pro cycling championship, and Horowitz was mesmerized. As the riders struggled up the hill past the water stations and through the cheering crowd, Horowitz imagined himself among the pack, his calves straining, his quadriceps burning.
"I just knew riding that race was something I had to do," said Horowitz, 34.
On Sunday, 22 years later, Horowitz expects to realize that ambition when he pedals off at 9 a.m. in the 26th TD Bank Philadelphia International Cycling Championship.
Billed as America's biggest single-day bike race, the championship will feature 20 teams and 160 riders zipping around the 14.4-mile course for a total of 156 miles.
Starting and finishing on the Benjamin Franklin Parkway between the Art Museum and Logan Circle, the race takes riders along Kelly Drive, through Manayunk, up the famous Wall on Lyceum Avenue, and back through Fairmount Park.
After that fantastic day on the Wall in 1988, Horowitz, who grew up in Philadelphia but has lived in Los Angeles for the last 15 years, immersed himself in the sport.
He began to train immediately, and took part for the next few years in the junior events on race day, spinning around Eakins Oval as the pro riders rode the course.
And when his father became a race official, he got to hang in the feed zones and watch Greg LeMond and Lance Armstrong operate. He loved it.
However, by the time he entered New York University, Horowitz realized he was a good rider but not an elite one. So he quit the bike and spent the next four years in college.
After college, Horowitz took off for L.A. to become a movie director. And when that effort stalled, he climbed back on the bike and into competition. Maybe, he thought, I could go back and race in Philly.
So, for the last 10 years, Horowitz has worked as a cycling coach and rider. But, despite intense training, he still was not fast enough to earn a pro contract and an invitation to the championship.
In 2008, another light went on.
He started his own team, got financial backing from Boston-based Adageo Energy, and signed himself to a pro deal. Now he's coming back to compete for his own team in uniforms he designed in what he calls the biggest race in cycling.
"I've raced in Sweden, Turkey, Cuba," Horowitz said, "all with the idea in my head of going back to Philly. And now I'm doing it."