Originally Posted by
Rick Imby
Multiple runs on both bikes with the same workout level will give a range as to the difference. I agree the results will not be perfect. There are too many factors to eliminate. However 5 runs on this ride on each bike will give a pretty good idea of the difference in efficiency----for me.
It should give you a good idea of the relative efficiency of those two bikes, but not any general conclusion about 700c vs. 20" bikes overall. As I wrote previously, my 451mm wheeled bike is in between two of my 700c road bikes in speed when ridden with the same amount of effort. Wheel size is only one factor and others such as body positioning, tire choice, frame flex, etc. will also influence the overall efficiency.