(CNN) -- The "girl on bike" is a familiar trope in the motorcycle world, which is why the editor of American motorcycle blog Asphalt & Rubber didn't pay much attention last year when images surfaced of a woman draped across the latest Ducati.
But when the dealership responsible for the sexy images re-created them using men -- all bulging muscles and body hair, farmers' tans and booty shorts -- they caught his attention.
These were the images he wanted to talk about.
"The conversation I really wanted to have is if you can put a girl on a bike, you should put a guy on a bike. And, if that looks silly to you, (then) you should rethink the other," said Jensen Beeler, editor of Asphalt & Rubber.
"I'm kind of tired of the 'pinup girl on motorcycle' theme that our industry does, so it was kind of fun to see someone poke that in the eye," Beeler said.
"I thought to myself, these are guys with a good sense of humor. They're not afraid of pushing boundaries, which is what motorcycles are all about."
But the images didn't go beyond the motorcycle world until just last month when they became a viral sensation. You probably saw them on Facebook or Twitter or on one of numerous news websites that showed them off.
The overwhelmingly enthusiastic response was far different from the one Beeler got on Asphalt & Rubber in August 2012 when reactions ranged from, "It's nice to see it go the other way for once," to "Why oh why!!!!! Really?????? WTF!!!!!!!!!"
Or, as one American motorcycle PR firm said, "Half of this made us throw up in our mouth a little bit."
But where did the photos come from, and why did they surface again now?
Both sets of images were the brainchild of Arun Sharma, general manager of MotoCorsa, a Ducati dealership in Portland, Oregon. Last year, he wanted his shop to be the first to circulate promotional images of the hotly anticipated Ducati 1199 Panigale. He wanted them to be sexy but tasteful, so fans wouldn't have reservations about using them as wallpaper on their office computer.
"It's not a big secret that beautiful women and motorcycles go together, but we're not into G-strings," Sharma said in a phone interview. "There are smarter ways to go about it."
Photographer and "Moto Lady" blogger Alicia Mariah Elfving helped style and shoot both sets of images. She also wanted to distinguish the photos of the female model from the "pervy images" that have defined motorcycle marketing; she prefers to see women riding bikes rather than hanging off them, she said. But as long as women were modeling, "we wanted to do something that was classy and better looking, so the content would be accessible to a wider audience."
They shot the photos the same day the Panigale arrived in the shop. Sharma said he achieved his goal of being the first dealership to circulate images of the hottest bike on the market, bearing MotoCorsa's name and logo.
As they spread throughout the world, much of the response was positive. There was some backlash, too. Tasteful or not, some said it was just another set of images of a model draped on a bike.
Inspiration struck Sharma a few weeks later, he said, in one those "You know what we should totally do?" moments: "We should totally do the same poses with the guys in the shop."
As Elfving remembers it, they had talked about the idea of responding to the backlash by reversing the gender of the models.
"Most people loved it, but others were like, 'Oh, a chick on a bike,' " she said in a phone interview. "OK, we'll give you something different then."
Sharma called a meeting and announced the plan to reshoot the images using MotoCorsa employees. A few refused to take part, he recalls, but most were enthusiastic. They drew numbers to choose who would pose for each shot. Senior technician A.J. Ralston was one of the last to choose. He is pictured precariously perched on all fours on the bike's seat.
"I thought it was a fantastic, hilarious idea," said Ralston, who has worked in the shop for 11 years. "It seems like we always get a lot of flak from customers whenever we put something up on our Facebook page that has a beautiful woman on a motorcycle, so making light of all of that and having a good time doing it seemed like a good idea."
Holding the pose proved to be a challenge for the 5-foot-10-inch, 230-pound technician, especially in slingback shoes and booty shorts.
"It was that kind of day, when it was super-hot outside, so holding a pose like that with sweat everywhere and my knees slipping all over the place gave me a new appreciation for what models do," he said.
Both versions of the images remained popular within the motorcycle community, sparking a few copycat male pinup shoots. It's not entirely clear why the images resurfaced again recently.
Beeler from the Asphalt & Rubber blog said his referral traffic showed it got moving on Facebook, caught on in S&M social media circles, then moved into feminist media, catching the attention of mainstream media outlets.
Sharma said he is thrilled with the renewed attention. There's been some negative reaction toward both versions, he said, but much more positive attention, overall.
"We just did it for fun, for the notoriety, and it went crazy," he said. "A lot of people have turned it into something it wasn't intended to be, but that's the beautiful thing about artistic interpretation."
Beeler said he hopes it's a wake-up call to the motorcycle industry that female riders might be attracted by a more balanced approach to marketing.
"If you want more gender equality in the consumer base, we have to have more gender equality in marketing and the way you're approaching things," he said. "Gender roles are still an issue that people find relevant, and I think that's why we saw it getting picked up in niches and exploding from there."