RIYADH — A half-moon directly overhead glows in the gathering daylight as Adel Mallawi straps on his helmet.

His tall legs, sheathed in leather chaps that match his black leather jacket, drape over one of the loves of his life: Harley-Davidson’s 105th anniversary Electra Glide Ultra Classic. Copper and black. Same colors as his helmet.

Birds chirp and a solitary trash truck gorges on rubbish in the empty downtown street as Mallawi and 12 other bikers, most of them Saudi, rev their engines. “Yallah!” someone yells. “Let’s go!”

The sun rises as the bikers ease onto the highway for a 750-mile ride through the Saudi desert to the United Arab Emirates to join hundreds of other bikers at the ninth annual rally of the Middle East Harley Owners Group (HOG). As they thunder toward the horizon, the crisp dawn air promises a perfect day on the open road, which Mallawi, a banker, finds exhilarating.

“It’s the sense of freedom you get on the bike,” the 30-something Saudi says. “It’s just you and the air. It’s a great feeling.”

America’s ultimate icon of letting loose, the Harley-Davidson, has gone from Milwaukee to the land of Mecca and Medina. Dire warnings from religious conservatives about the sinful pitfalls of imitating a Western lifestyle are no match, it seems, for the allure of soft leather, gleaming chrome, and the purr of a perfectly pitched motor.

“First of all, the bike is beautiful,” says Marwan al-Mutlaq, owner of Riyadh’s Harley-Davidson showroom. “You love to look at it.”

In 1997, Mr. Mutlaq’s family, which holds the Harley-Davidson franchise for Saudi Arabia, Bahrain, and Qatar, opened three stores. They sold 60 bikes. “Now, we’re hitting 500” a year, he says.

The sun rises as the bikers ease onto the highway for a 750-mile ride through the Saudi desert to the United Arab Emirates to join hundreds of other bikers at the ninth annual rally of the Middle East Harley Owners Group (HOG). As they thunder toward the horizon, the crisp dawn air promises a perfect day on the open road, which Mallawi, a banker, finds exhilarating.

Mutlaq, who keeps his favorite bike, a cherry-red Screaming Eagle, in Europe, and who once rode from Saudi Arabia to Ireland, also heads Riyadh’s Harley Owners Group. The chapter started four years ago when the showroom opened. It has about 300 members, 60 percent of them are Saudi. As befits the country’s nascent biking culture, most are clean-shaven, short-haired, and tattoo-free, though one member sports a helmet decorated with skulls.

Saud bin Driss, a young employee of an investment firm, says his initial impressions of Harley riders were formed by Hollywood: “Mostly gangsters … very dark,” he says.

But when his cousin announced he was getting a Harley, Driss says, “as a competition to him I saved my money and got one.”

Although Driss’s family is conservative, they encouraged him to get a Harley because “they know some of the people here and what their mentality is; that they’re mature men, not like 20-year-old kids with speed bikes” who might be “a bad influence.”

Every Thursday morning, the start of the Saudi weekend, Riyadh HOG members gather for coffee and doughnuts – purchased from the Dunkin’ Donuts across the street from the dealership.

On Fridays, they gather for group rides. Recently, members drove about 60 miles west of the capital city to a desert rendezvous. The road wound past date-palm groves, high-walled farms, and tiny villages, where young boys darted out of alleys, and old men stood in shop doors watching the bikers roar past (at the speed limit).

The destination was a tan-hued mesa, where a tent with carpets was awaiting. Laughing and gabbing, the riders pose for a group picture.

Mutlaq, clad in blue jeans and a Harley T-shirt – rather than his usual garb of a long, white robe – calls for the midday prayer. The Muslim motorcyclists gather on the carpet for their religious duty, with the Christian riders standing at a respectful distance. Then, a catered lunch is served.

Expatriate riders say the Saudis make them feel welcome. “The guys look after us expats really, really well,” says David Tasker, a Briton. “When we go for a ride, they like to show us the country and customs.”

Mutlaq says the first day he opened his store, the religious police dropped in to check it out. But they don’t bother him now. There’s no reason they should, he adds, because being Muslim doesn’t mean “I stop living … I can still ride and live my life.”

Mohamad N. Chbib, a business operations manager at Cisco Systems’ Riyadh office, says that because motorcycling is a relatively new sport here, “people tend to not respect riders” because of the stereotype “that they’re very grungy; they’re outlaws.”

He and other bikers are “trying to change that perspective … the majority of [riders] are executives and engineers and doctors,” Mr. Chbib says. “We’re trying to deliver the message that Harley-Davidson is a brand name, is a bike, is a lifestyle, that you can custom-make according to the culture that you live in.”

Mutlaq tells the story of a Harley rider who drew glares from a driver when both were stopped at a traffic light. The driver, Mutlaq says, asked the the rider, “Aren’t you ashamed to be on an American product?”

The biker replied: “Well, you’re in a Ford – don’t you know this is made in the States?”

Mr. Tasker, the motorcyclist from Britain, says he only recalls having problems once. That was a year ago when Saudi Harley owners held their first annual rally in Jeddah, and some of the foreigners had wives riding on their cycles.

“The police weren’t really used to women riding on the backs of their husbands’ bikes, so we kept getting stopped,” Tasker recalls. “They wanted to make sure the couple were married and that there was no hanky-panky going on. … There was no animosity. They were just unsure of what the rules were.”

Saudi law forbids women from driving four-or two-wheeled vehicles.

Chbib says he and some other Saudis take their sisters, wives, and daughters for rides on their bikes.

Not all Saudi bikers believe that’s a good idea, Mutlaq says, adding, “We don’t encourage that ourselves at the moment” because they are trying to follow “the practice of the country in all aspects.”

When the chapter holds events to which bikers’ families are invited, the women arrive in buses or cars. And there are separate “family sections” and “single men’s sections” for dining to comply with the country’s strict gender segregation.

“When do you think women will be riding motorcycles in Saudi Arabia?” is the question that Mutlaq says he is asked the most. “And I always say that it will be the day after they allow them to drive cars.”