Bish, your rides are impressive and your mapping tools is clever. 52 miles at over 18 mph on that route says you've got it!

Does the group ride convene in Belmont or Concord? How many folks ride? I ride in groups occasionally and the impact of the group on my speed varies. One group of about 8 riders rides "loose" and very rarely call out traffic or pavement conditions (yoyo or "your on your own") until we get tired then the last 1/4 of the ride bunches up and gets more organized to take advantage of wind reduction. There are 6-8 riders and it is aggressive riding. Two other groups of 2-4 riders tend to tuck right in and in one case we work hard but I don't feel in the end my average time is better than if I ride alone. It seems the close quarters riding and maybe pushing up hills takes more effort than my solo or "loose" group rides. Another small group rides tuck in and it clearly helps; average speed seems 1/2 to 1 mph faster than solo or loose.