On a dark October night last year, Cynsa Bonorris was cycling home after a dinner party. Keeping an eye out for traffic, she approached 7th Avenue at Lawton in the Inner Sunset – when she received an unexpected, impromptu and painful lesson in physics.

“Right in the intersection was a huge gully, and it caught and stopped my bike, and I went flying like Superman with my bike tangled between my legs,” she said. Unlike Superman, Bonorris’ brief airborne interlude ended with an all-too-human landing. The jarring crash left her with a mangled pinky finger that required two pins to reset properly, a torn rotator cuff requiring six months of physical therapy, and a newfound paranoia born of the realization that just watching for cars wasn’t enough to ensure her safety as a cyclist.

“I ride my bike everywhere, everyday, for everything,” she said. “I spend a lot more time looking at the road now and not traffic, which isn’t very good, and I’m very paranoid because the healing process was so long.”

On April 19th, Bonorris met with 50 other volunteer cyclists at Civic Center Plaza to put that paranoia to rest through “An Attack of the Crater Invaders” – an event organized by the San Francisco Bicycle Coalition that saw eight teams of cyclists riding different routes throughout the city, marking potholes and other bike hazards with neon-colored liquid chalk sprayed over stencils.

Addressing the volunteers before the ride, Neal Patel, the coalition’s community planner, said, “We as bicyclists have a different threshold for road conditions. We’re using the stencils to create awareness for bicyclists and pedestrians to show there are a lot of dangerous areas out there.”

The coalition has long employed volunteer “lane stewards,” members who report unsafe road conditions and worn-away bike-lane paint through the city’s 311 services number, but Saturday’s action was the first large-scale event focused specifically on scouting out large numbers of road hazards.

“We now get more complaints about poor pavement quality than about car-bike problems,” said Leah Shahum, executive director of the coalition. “One of the things we’re focusing on today is a better response time from the city.”

Edward Reiskin, director of the Department of Public Works, made an appearance, drawing applause for the work the department has done to address road-safety issues. He said the department is currently looking into resurfacing damaged bike lanes throughout the city. “I’ve met with Neal and Leah and we’re working with the street and sewer detail to focus on problems,” Reiskin said. “Whatever role public works can play is a big part of what we want to do.”

Patel will be submitting a list of every stenciled hazard to the department this week. Next month, the coalition plans on going back to check the areas and will publicize their findings. He estimated that the teams marked 60 problem areas and covered over 50 miles of road on Saturday.

During Saturday’s “attack,” Shahum led a wind-battered group of five cyclists along a route that wound through the Mission District.

For Marlise Kuert, 34, and her husband, Peter Kolb, 33, the streets of San Francisco came as a shock when they moved here from Switzerland. “I bought a second bike for commuting just because the streets are so bad,” said Kolb, who rides from the Inner Sunset to UCSF’s Mission Bay campus during the week. Both are coalition members who stated a strong dislike for driving, and have never owned a car.

Brita Thompson, a 20-year-old English major at USF, had attended Critical Mass rallies before, but this was her first Bike Coalition event. “I’m really kind of a cautious rider,” she said. “This makes me feel safer, and even if I didn’t [personally] do one, it’s cool to go out on Market Street and see the paint and you feel like you’re a part of this community.”

As Shahum’s team rode down Valencia Street – currently in the midst of a large repaving project – it quickly became apparent the problem wasn’t finding hazards, but picking which ones to mark. A wide crack at Valencia near 20th Street was stenciled with the words “Call 311 to fix me” in day-glow orange.

Other stencil designs were less literal. One depicted a pair of reptilian-looking hands looking for something to grab onto; another was the top and bottom jaws of a monster, suitable for framing the edges of potholes.

And though she was essentially performing a public service, it was obvious Shahum was working out some personal vendettas as well.

“This … is the bane of my existence,” she said, pointing to an amorphous blob of asphalt at the corner of 13th and Harrison streets. A part of her daily commute, the 3-foot-diameter patch dipped into a low bowl before rising sharply like a frozen wave about to crest.

“Sorry to be so selfish, but this one drives me crazy!”