The for-profit event lost money last year, he said, largely because of the increasing cost of city services, such as police overtime and sanitation. The city has required most events to pay those costs since 2009.
TD Bank also ended a four-year deal as title sponsor in 2012, and Chauner has been unable to find a new lead backer to cover about 60 percent to 70 percent of the race's $1.2 million to $1.5 million budget.
"We're five months out now. . . . All of the logistics that are required to put the race on, it's just impossible," he said. "If we're going to bring it back, we're going to bring it back in a high level of professionalism."
Chauner would not say how much money the race lost in 2012, but said organizers could not cover a $300,000 bill from the city, which he said included a last-minute $88,000 invoice.
That invoice "is not something we could handle," he said. "The event cannot be sustained on a loss."
The race also has become known for partying and drunkenness that accompany it. Police presence was doubled, Chauner said, and neighbors have said the last two years were much calmer.
But the extra police strength has been expensive, Chauner said. He said the race reduced other costs by 10 percent as the price of city services rose 60 percent and became difficult to forecast.
"I think there could be a lot better dialogue between the city and event organizers," he said.
Mark McDonald, a spokesman for Mayor Nutter, would not comment at length Monday, saying "the administration will have something to say about the situation" Tuesday.
People began to learn that this year's race was canceled after Philly.com posted a story Sunday. The story was first reported on cyclingnews.com.
Jane Lipton, executive director of the Manayunk Development Corp., said she read the news in an e-mail from Chauner at 7 a.m. Monday.
"Just as I was reading it, I saw it on television, like everybody else," she said. "I was really surprised."
The race has been held for 28 years and helped reinvent the neighborhood in the 1980s.
For bikers, the race and the neighborhood are symbolized by "the Wall," the brutal half-mile climb up Levering Street and Lyceum Avenue that attracts and tests professionals and amateurs alike.
"Every day, somebody is riding a bike up that wall," Lipton said. "I don't care if it's snowing outside."
Losing the race - and the visitors, revenue, and attention that it brings - would be a psychological and economic blow to the neighborhood, she said.
"I would never say never," Lipton said. "This is a big city. We have a lot of potential title sponsors out there."
The race once was known popularly as the "CoreStates," after the former bank that was the title sponsor for the first 20 years. In 2006, with the urging of Gov. Ed Rendell, Commerce Bank, later bought by TD, picked up the sponsorship.
Seeking to reinvigorate the event, Chauner last year shortened the race and allowed amateurs to pay a fee to bike the course before the pros set off.
He said the event must continue to be reinvented, stressing a broader weekend of activities that appeal to recreational cyclists. He said a marketing firm had been hired to put together a package that could be taken to potential sponsors.
Juliet Sabella started an indoor cycling center last year called the Wall Cycling Studio. She said she could hardly imagine Manayunk without the race.
"It would take away from everything Manayunk does," she said. "It's a part of Manayunk."
Contact Troy Graham at 215-854-2730 or firstname.lastname@example.org, or follow on Twitter @troyjgraham.