Facebook. Once you like, follow and/or join one bicycling group, Facebook will suggest others. Pretty soon you'll see more than you could ride in a week.
It's pretty easy to ignore the drama on Facebook if you want to just focus on the group events that interest you.
1. Assign priority to the groups and people you want to hear from first. Those will deliver push notifications, which is helpful for group rides, especially when times or start/finish locations change.
2. Assign regular priority to everyone else.
3. Unfollow or mute the people you want to *appear* to be friends with, but don't actually want to see their posts too often. That includes most of my relatives. It also includes the filibuster posters who post dozens of times a day, every thought that pops into their noggins or annoys them during that particular 5-minute period.
4. Get off FB for the day after reading what you want. Most FB pain is self-inflicted.
I rarely unfriend anyone but I'll occasionally use the option to mute them for 30 days if they're on a crapposting binge. I don't even mind if folks post rants about hot button issues, as long as they confine it to one or two a day. But some of my friends post literally dozens of political rants every day. I love 'em even when we disagree, but when they drown out everything else I'll mute 'em or unfollow them for a few weeks. I'd prefer it if Facebook would condense everyone's daily allotment of crapposting under a single tab. Sometimes I actually want to read rants on politics, economy and religion -- my friends are pretty intelligent folks and have something interesting to say. But not when it drowns out everyone else.