"People were buying tickets knowing that they weren't going to be able to see the screen," recalls Filmed by Bike founder and festival director Ayleen Crotty. When the cycling-centric film festival Filmed by Bike debuted in 2003, Crotty's humble expectations—she hoped 30 people would show up—were shredded by the gargantuan turnout. "We were onto something that was worth continuing."

Talk about an understatement. Filmed by Bike—which returns Friday to the Hollywood Theatre—is celebrating its 15th anniversary this year. It has grown remarkably since its debut, transforming into a celebration of biking worldwide that features 80 short films hailing from a long list of countries that includes India, Sweden, England, Kenya and Japan.

Which is a long way from where the festival started. Crotty admits its early years were filled with "trick riding on BMX bikes, urban trick stuff, mountain bike videos"—all of it in films that she says were "really fun to watch but did not have a lot of substance behind them." That seems to have changed, thanks to a diverse slate of movies divided into several different programs. These include "World's Best Bike Movies," "Adventure Night," "Race to the Finish" and "Triumph," which evokes the event's international scope with films like My Ride, which takes a look at an all-female Muslim cycling club in London.

That doesn't mean Filmed by Bike has abandoned its roots—it features Oregonian efforts like Dirty Sellwood: You're Never Gonna Make It, from Hood River filmmaker Manny Marquez. It is nominated for the festival's top prize, the Golden Helmet.

Yet Crotty says the festival's movies are largely non-local now. One of this year's most entertaining and illuminating entries is Voice Notes: A Tandem Ride With Horst A. Friedrichs, a moving film from Spain about the titular bike-adoring photographer.

Although she says that hasn't helped her get submissions from bicycle-centric Amsterdam. "People in Amsterdam don't make films about biking, because to them, biking is just like drinking water," Crotty explains.

Could Portland be headed in that direction? It's hard to say, though Crotty says "if we get to the point where people no longer have an interest in making bike movies…I think that will be a victory, because it will mean that cycling is so common that we don't have to make movies about it."

"But I don't really hope we get to that point," she concedes, "because we're having so much fun as it is." 

SEE IT: Filmed by Bike is at the Hollywood Theatre. May 5-7.

See filmedbybike.org for a full schedule, tickets and passes.