A crowd of partying cyclists overwhelms downtown streets (and runs through a few red lights).

Hundreds of people dressed as robots gathered in the rain in Dupont Circle last week for a bike ride. They were not afraid of rust.

They fearlessly took over the streets for the latest D.C. Bike Party (Dcbikeparty.com), a freewheeling bash accompanied by pedicab-bound DJs that happens the second Wednesday of every month. The event always has a theme, and this time, the bike-towed speakers blared Daft Punk to celebrate the French DJ duo’s new album, “Random Access Memories.” The crowd dressed accordingly, covering their bicycles in glowing wire and tricking out cardboard boxes with duct tape, third-grade-style.

That youthful enthusiasm is a hallmark of these affairs, which have snowballed since their inception in July. Sure, there are other opportunities to put on a costume and speed alongside speakers — Bicycle SPACE’s 7th Street Socials, for instance, held every Thursday. But those are rides, and this is a party.

And everyone’s invited, says D.C. Bike Party founder Lia Seremetis, who was inspired by the booming bike parties in her hometown of San Jose, Calif., and in Baltimore. Seremetis says there’s no need to be a bike pro — she didn’t start biking until a year ago and only recently learned to pump her tires.

“Literally anybody who knows how to ride will come out,” Seremetis says. “People are always asking me, ‘What if I don’t have a bike?’ You live in D.C.! You do have a bike! Bikeshare!”

The all-are-welcome attitude has a few negatives, such as the rookies who show up without helmets. That can be scary, especially around a large group of inexperienced cyclists who are starting and stopping abruptly, wearing unwieldy costumes and surrendering themselves to the power of rave music.

Costumes, above, and a DJ spinning Daft Punk, below, add to the atmosphere.

D.C. Bike Party’s website lays out the rules of the road, which include stopping for red lights and staying in one lane, but it was clear last Wednesday that robots don’t always follow traffic laws.

They are, however, a lot of fun to cruise around with. Halfway through the 8-mile ride, everyone dropped their bikes on the Mall for a spontaneous dance party. In the throng was a guy who’d brought along his pair of ferrets; he put one on a woman’s shoulder and let her take the pet out for a spin.

“It’s very joyous,” Seremetis says. “There’s no negativity. The vibe is very happy, very welcoming.”

After the bike party, of course, comes the regular party, with the riders descending on a predetermined bar. Last Wednesday, it was The Brixton on U Street.

This is where Capital Bikeshare users have a distinct advantage. They get to fill up docks instead of competing for bike parking with the rest of the group, and they don’t need to worry about riding home.