Since June, my moving average over 25 to 30-ish mile rides has been between 15 and 17. Total average is lower since I always take a stop here and there. That's over basically flat land with a few little bumps that don't qualify for real hill status but cause me to wheeze mightily nonetheless... Never done any rides of significant length... maxed out so far at 51 and 54 miles, but I sense a metric try coming up this fall.