Madison Area Ride Groups

West Side

Wingra, Heron, Hops and Derailleur Society (WHHDS) - early morning weekday rides and Saturday rides
Women on Wheels - weekday evening rides led by women

Slow Roll Cycles - rides, usually at least partly off-road, leave at 6:20pm on Tuesdays. Weekly details can be found on Facebook.
Black Saddle - they seem to tend to ride on Thursday evenings, but they post rides on Instagram when they happen.
Machinery Row - they run a couple rides, including the Century Training Club, which ramps up to doing the Door County Century in September.
Motorless Motion - Taco ride leaves at 6pm on Wednesdays.
Brazen Dropouts - Saturday morning fast Row ride leaving from Machinery Row at 9am.
Madtown Mondays - party pace group ride leaving from Orton Park on Monday afternoons, though it may be worth confirming whether it is happening this year.