Today my 10 year old did his longest ride ever on the back of our tandem--about 34 miles @ an average pace of 16mph (and he said he wasn't too tired by the end...not a single complaint during the entire ride). Tomorrow we are doing a 30 miler on a mix of pavement and gravel. After tomorrow he will have logged well over 100 miles in less than a week's time. Lotta power in those skinny legs. He and his dad could easily drop me (and sometimes do).