Almost all the "invitational" rides clubs and orgs put on are definitely not races. Folks in the front can and do ride as fast as they can, but - no prizes, no mass start, so in a way that's there idea of a "just for fun" ride, too.
Generally there are fast riders and then all the rest of the world, and it's good company among the masses that are just trying to challenge themselves.
I have a strong preference for rides put on by bike clubs because they tend to know what is important. Many of the rides that a local lions or rotary club puts on will not realize that oh, that stretch of a mile of gravel is horrible to ride through (and by turning south a mile earlier, we avoided it) and... oh, saying your family route is 16 miles when it's 23 will mean those folks aren't coming back... and the rest stops at a club's ride are going to have Gatorade or Powerade and trail mix, not the donated-from-McMaggots orange clot and who knows what to eat... oh, and club rides haven't closed up their rest stops before I got there (and before the time they said they'd close). (These weren't all the same ride, fortunately - but there's a pattern there.) I *do* be sure to have my own "reserve bottle" of Gatorade or whatever because sometimes they run out of something when I'm pulling in.