We've got a pretty large local club, Bicycle Touring Club of North Jersey, just over 2,000 members. Rides are graded A-D for average speed, in general faster rides are longer and hillier. A=17+, B*=15-17, B=13-15, C*=11-13, C=9-11, D=<9. In my youth/prime I could never hang with the A riders but B* rides were fine. 30yrs and a lot of pounds later, a hilly B ride hurts and just ain't fun. There is a lot of Strava madness in the higher categories, so avg speeds are often a full category higher than advertised. I'd rather be comfy on a C* ride than sucking wheels on a B ride that's averaging 16mph.

46mi today at 12.9mph with 1,700' climbing on a 69" fixed gear was fun and tolerable. Club half-century last week 58mi @ 13.6mph w/2,000' climbing, on same 69" fixie, was fun, but most of the climbing was at the end and my legs/knees complained for the next few days. Gears will get me a little bit faster and a little further, especially when it's hilly. But I learned a long time ago that folks like me who slow down when it hurts never go as fast as those that hammer faster through the pain. Never had that switch in my brain, can't say I've missed it.