I don't have trouble believing that it is possible on that bike. 20mph isn't actually that fast for a reasonably fit person when all is said and done.
What I do find slightly odd is that his minimum speeds seem to bottom out at around 8mph which seems to me that he has set his Garmin to stop timing below 10mph which means that if he takes his time on the hills, they won't be counted.
I'd like to see how he does with his Garmin set to record at all speeds.
I don't have trouble believing that it is possible on that bike. 20mph isn't actually that fast for a reasonably fit person when all is said and done.
What I do find slightly odd is that his minimum speeds seem to bottom out at around 8mph which seems to me that he has set his Garmin to stop timing below 10mph which means that if he takes his time on the hills, they won't be counted.
I'd like to see how he does with his Garmin set to record at all speeds.