From SFBC:

Want to cycle in the city but feel uneasy about it? Join the Gals for an enjoyable ride along Embarcadero to the Marina and back. We’ll show you a route, provide tips for riding in the city, and have a relaxing and easy ride. This is a no drop ride. Gals with Gears is a group of women 50+ years young seeking fun, healthy and practical bicycling in San Francisco — with women our own age! Distance: approx 10 miles, helmet required. This is a no drop ride.