At first, she thought she might be hallucinating. Kristin Sugden had heard a lot about the party atmosphere surrounding the annual Philadelphia bike race, but she was new to Manayunk and hadn't yet experienced the wild bacchanalia in person.

Sugden threw a party for some friends last year, but by midafternoon - as international riders fought fatigue and struggled to climb Manayunk's mighty Wall - her house was packed tight with about 50 people, almost none of whom she knew. Sugden left her roommate with the random crowd for a moment and went outside for a quick but much-needed respite and some fresh air.

That's when she encountered a tall, skinny, pale man in a Viking costume. He wore a helmet with horns and brown lace-up boots. He accessorized with a backpack to hold his beer, and there were beach tags on the bag - possibly, Sugden theorized, so he could return to his ship without getting hassled. And, in an appropriate and historically accurate nod to the time period, he was skipping rope with a telephone cord.

"It was crazy," Sugden, 25, said. "Later on, my friend wandered down the street and saw a huge naked dude in a kiddie pool."

Almost everyone who has been to the bike race in Manayunk has a similar story, one of debauchery and strange sights. You're as likely to encounter some guy dressed in diapers as you are to see an actual child. These days, the slogan for the event might as well be something on the order of: It's Race Day, Manayunk - Let's Get Weird.

Certain members of the community aren't so thrilled about that. Sunday will mark the 27th installment of the Philadelphia International Cycling Championship, which starts at Logan Square and winds down Kelly Drive and into parts of Manayunk and Roxborough for a 14.4-mile loop that riders from 30 countries will attempt to complete a staggering 10 times. Some Manayunk residents believe Philadelphia's cycling showcase has deteriorated over the last 10 years from a family-friendly event into open-air anarchy where underage drinking, public intoxication, and disorderly conduct are commonplace.

Jane Lipton, executive director of the Manayunk Development Corp., said the Bike Race Committee - a newly formed coalition of community activists and local-interest organizations - hopes to "dial back" the unruly behavior. Until a few years ago, the night before the race was marked by an underground race called the Brakeless Bike Party. College kids and fearless drunks prepped for the next day by hurtling down the Wall on all sorts of homemade contraptions - everything from recliners outfitted with wheels to sofas to moving dollies. The cops shut that down a few years ago, but other problems persisted.

Among those issues is what City Councilman Curtis Jones Jr. called "speakeasies" - house parties advertised through Facebook and other social media, where $10 at the door gets you a cup and access to kegs in some stranger's backyard without having to provide ID or answer questions.

"This year," Jones said, "we want to make sure our best foot, so to speak, is put forward on the pedal."

In an effort to do so, residents have been getting robocalls in the voice of Deputy Mayor Everett Gillison reminding them to please enjoy the race responsibly. A "bike court" - think Eagles court, only without Seamus McCaffery and the Vet's concrete charms - has also been established at Fifth Police District headquarters at Ridge Avenue and Cinnaminson Street. Last year, just five citations were issued. This year, if you're planning to attend the race, you might not want to urinate in public - or, if you do, you should bring $300, the approximate starting rate for those types of violations.

"We're making it clear we're not going to tolerate a party atmosphere," said Lt. Sean Lynn of the Fifth Police District. "We have a zero tolerance policy."

Kevin Smith, president of the Manayunk Neighborhood Council, said that's good news. But, like a lot of unhappy residents, he remains skeptical. At a town meeting days before the race, he expressed his displeasure.

"This year, show us something or we'll start working on shutting down the race or moving it out of Manayunk," Smith said. "If people behave on other parts of the route but not in our neighborhood, why would we want it? If it's not doing Manayunk any good, it can go elsewhere."

That, said David Chauner, president of the Pro Cycling Tour LLC, the governing body for the race, would be a huge blow to the community (not to mention faux Vikings and flabby nudists).

"It's not just the bike race, it's who's moving into the community and renting the houses there," Chauner said. "That's a big part of it. Getting rid of the bike race won't change that, and it would be a big blow to the city and a big blow to Philly and Manayunk if the race didn't go through Manayunk anymore. . . . You don't want Manayunk to get labeled as a community of rowdies that are basically driving good events out of the area."

Contact columnist John Gonzalez at 215-854-2813, gonzalez@phillynews.com, or @gonzophilly on Twitter. Read his past columns at philly.com/gonzo