When it comes to "averages" I've seen everything from a supposedly social group ride in Florida that was advertised as 18-20. And you should have heard the complaining if someone at the front dared to go 20.4 for any period of time. To, this past weekends 15.6 mph average that saw everything from 10mph up hills to 35+ on the decents and periods of a couple miles at a time with paceline speeds of around 25+.
Just show up. Talk whoever's there and go have fun.
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Birth Certificate, Passport, Marriage License Driver's License and Residency Permit all say I'm a Fred. I guess there's no denying it.