In the midst of a recession and with loads of empty hotel rooms, South Carolina's vacation hot spot is hanging a "No Vacancy" sign for hundreds of thousands of motorcycle riders who have come here each May.

Over the past year, officials have outlawed parking lot gatherings, loud mufflers and riding without helmets — all in an attempt to keep the bikers out.

Even with the city's new measures, motorcycle riders are expected to show up for two of the nation's largest rallies: one traditionally attended by white bikers on roaring Harleys, the other by black bikers on screaming sport cycles. But for the white biker rally that begins Friday, tourist-dependent business owners are uneasy because bookings are down a third from last year.

"At a time like this, you can't pick and choose the tourists you want. You take the ones who are going to come," said Robert Kelley, who owns three hotels and a restaurant.

The recession is only the latest wrinkle to hit the Myrtle Beach bike rallies. The fight has been brewing for years as the region's year-round population mushroomed and its tourist industry tries to change the city's image from weekends of muscle shirts and budget motel stays to khakis and top-notch golf courses.

Residents fed up with the noise and traffic that choke roads up and down the 60-mile long Grand Strand in northeast South Carolina say there is no normal life for weeks. Some shut themselves inside or leave town.

"I don't sleep for three weeks," said Birgit Darby, a 78-year-old retired magazine owner who lives a half-block from the main commercial drag through Myrtle Beach.

Darby said she has watched the rallies go from a nice seasonal diversion when she moved to the area 50 years ago from Denmark to a seemingly endless orgy of window-rattling mufflers and half-naked female biker companions. Critics complain about the visitors having sex in parking lots, women baring their breasts and innumerable contests involving wet T-shirts.

"This whole thing — it just built into a frenzy and got out of hand," Darby said. "It's really a shame."

Traffic fatalities and citations do increase during biker week, though arrest numbers for other illegal activity fluctuate each year.

The push for the local ordinances kicked into high gear after a white, 20-year-old Coastal Carolina University student was shot to death last May outside a Myrtle Beach house by two black teens during the height of the black, Memorial Day Bikefest. Arrests didn't come for nearly two weeks, and rumors started circling that the suspects were black bikers.

That it turned out the two suspects were locals — and weren't riding motorcycles — didn't slow residents who joined community groups and protested at public meetings.

In less than a year, the city raised taxes to pay for its fight and passed nearly a dozen laws, including a strengthened noise ordinance, helmet requirement and anti-loitering law aimed at making it miserable to hold any type of motorcycle party in city limits. Even parking for a few minutes to chat could be deemed illegal.

A publicity drive was launched to let people know the rallies were over: "Effective 2009, Myrtle Beach, SC will no longer host motorcycle rallies," a city-sponsored Web site read.

Critics say racism has a role in the fight, too, but the black bikers couldn't be pushed out without going after both groups.

The city has a rough history with the black festival. Three years ago, it settled a discrimination lawsuit with the NAACP after it used different traffic restrictions for the black biker rally. The civil rights organization also successfully sued several restaurants and a hotel, saying they either closed during the black biker week or operated differently.

"I do believe the underlying factor is they really want to get rid of the Memorial Day Bikefest, because it is highly attended by African-Americans," said Hakim Harrell, organizer of the black rally.

Other motorcycle supporters think the problems are overblown to help golf courses and high-end hotel owners at the expense of smaller operations that made the Grand Strand an affordable vacation.

Tom Rice, a 51-year-old tax attorney who led the anti-rally campaign, discounts the theories and points to the nudity and obscenities, saying they clash with the burgeoning mass of people who call Myrtle Beach home.

The rallies exploded in popularity in the past 15 years, peaking at about 500,000 bikers — at the same time retirees increasingly streamed into the area. The Census Bureau estimates 257,000 people lived in Horry County in 2008, an increase of more than 110,000 people since 1990.

"We don't care if tourists come on a boat, on a plane, two wheels, four wheels or no wheels," Rice said. "We aren't going to tolerate this. We don't want people who can't behave."

Occupancy rates for rental houses are down 30 percent during the first bike rally, although Memorial Day weekend bookings are running about the same, according to Coastal Carolina University's Center for Resort Tourism.

Some businesses that cater to bikers have fought back. They rented a banner plane at the Daytona Beach, Fla., rally earlier this year with the message "May is on, pass it on."

And there's been one unexpected result — white and black bikers separated by race and motorcycle style — have joined in a common cause.

"We've laughed about that, both sides," Harrell said. "They did something that we all never thought would be possible — that would be the black biking community and the white biking community coming together and being united — standing next to each other and saying we as bikers will not stand for certain things."