In the aftermath of Mr. Frazier’s death, other cyclists are attempting to mobilize politically, under the name “Woon Justice for South L.A.” Hundreds of cyclists across Los Angeles have joined in protests and vigils, and many are working to change city policy involving the protection of cyclists.

“We keep hearing, every week, about people getting run over or hit,” Mr. Barrientos said. “And the city isn’t doing anything, the law isn’t doing anything, and the public isn’t doing anything. So who is going to step up?”

Spencer Sims, a member of Chief Lunes, said “Woon Justice for South LA” had focused on the specific goal of getting a bike lane installed on Manchester Avenue, where Mr. Frazier was killed. The group has other goals: To petition for questions about cyclists on driving tests and to eventually start a legal defense network to connect cyclists and pedestrians who are hurt by reckless drivers.

“We don’t want other people to die. And there are people dying on their bikes all the time that aren’t part of any community so they don’t get any support. And we want to be able to be the voice for that,” Mr. Sims said.