Originally Posted by
TejanoTrackie
Let me suggest you try a coast down test to see the the overall drag is the same. Take both bikes to the top of a hill, and measure the time it takes to coast to some specific point at the bottom. Try to sit in the same relative position on both bikes to equalize the wind drag. If the bikes are actually identical, then the heavier bike will be a bit faster due the added propulsion force provided by its added weight.
Interesting. Seems like an accurate way to measure. But I'd have to limit the top speed (timing cutoff point) to the same speed that I am capable of generating myself though, right?
The "light and slow" bike does have much wider fork blades and bigger frame tubes than the "heavy and fast" bike, but would that matter from a a stop to 15mph?