Originally Posted by
aramis
This one is easy to answer.
For an accurate "internet average speed" look down at your bike computer a couple times when you're on a nice flat or slightly downhill stretch... assume you did that speed the whole ride. Easy!
Shoot, I'm a lot faster than I thought...
For the OP, the only way that seems honest to me is total miles divided by total time. If you ride 10 miles in 30 minutes, rest for 30 minutes, then ride back in 30 minutes, you've ridden 20 miles in 60 minutes. But I'd count my average speed as about 14.