Originally Posted by
StanSeven
There are so many variables, no one can make a comparison with just two rides on different days. For starters, your power can vary considerably and you may want one bike to "win". You need to keep power constant on both rides throughout the test. Fit between the bikes can make a huge difference. Rolling resistance between tires can amount to several watts alone. Even with everything else the same, six lbs of total weight (bike plus rider) over twenty one miles definitely makes a difference (go to one of the online models and calculate the time difference.
Very true- but the thing is: I ride in the real world; and this comparison was done in that world.....and there was not enough difference to be meaningful. I mean, in the real world [we don't ride under perfectly controlled laboratory environments] there will always be slight variations- such as the 12/100ths of a mile difference likely resulting from me taking a different line at some points- but the thin is: With results THAT close, it doesn't pay to worry about it, because the difference would mean so little in the real world. [If we were pro racers, then maybe we could gain a little something by being concerned with such things, to make more critical testing be worthwhile].