So I was the turtle.

[BleeckerSt_Girl]

I started a couple of months ago on a MTB and saw a gradual improvement in my time. ON my 20 mile a day ride I started to average 17mph on the flat parts.

Hey NO FAIR! Counting only "the flat parts" is no average at all! Your average is counting the whole ride, both hills and flats. Like, if I counted only my downhills I would be averaging 30mph instead of the 10mph I actually average including all the uphills and flats too!