Robyn- Dave and I went on the Natick ride this past week. They divided up into 17+ and below (ie us). Andy (my fitter) led us slow people- most of us were riding about 14-15ish with a couple that were slower but we'd wait for them at the turns. Andy's fast enough that he'd leave the 4 faster of us on our own a minute, fall back to check on the slower 2, then be back up to us in a flash. We did about 14.5 miles (with a good number of nasty hills) and I bet the faster crew did 20ish. Andy said once it gets bigger through the summer, they'll do 3 groups- basically adding a 20+ group to the 2 we had.