Critical Mass 2021 Halloween Bike Ride (SF)

Submitted by the Event Organizer

San Francisco Critical Mass

Critical Mass is a mass bicycle ride that takes place on the last Friday of each month in San Francisco starting at 5:30 pm at Justin Herman Plaza (foot of Market Street) and in cities around the world. Everyone is invited. No one is in charge. Bring your bike.

Please Note: Critical Mass tends to practice extreme bike power by taking to the streets and riding in the car lanes causing endless annoyance to motorists.

In San Francisco especially, this event can get HUGE. Consider this is fair warning to stay away from driving in the downtown SF area on the last Friday of every month.

Friday, October 29, 2021
San Francisco Critical Mass

Is this taking place in 2021? As far as we can tell, this event is back on for Halloween 2021 as the event is listed on sfcriticalmass.org as specifically taking place on October 29, 2021 at 5:30pm. But we don’t see it listed on their Facebook page which hasn’t been updated since February 2021.

Critical Mass is a mass bicycle ride that takes place on the last Friday of each month in cities around the world and since in October it typically falls right around Halloween, riders dress up and ride through the city as a costumed parade. There’s nothing officially organized, but just sort of “happens.”

Get your costume on (just make sure it clears your gears and chain) and meet at 5:30 pm at Justin Herman Plaza.

Critical Mass is argued to be a political protest for bikers’ rights, but it’s also a social ride that takes over the streets. Some love it and support it fully, while others detest it because it blocks traffic and disrupts the evening commute. If you choose to ride, please ride safely and obey the traffic laws.

Disclaimer: Please double check event information with the event organizer as events can be canceled, details can change after they are added to our calendar, and errors do occur.