Motor Output Watts For MPH

[Chalo]

Maybe it's just me, but I find the calculator at http://www.kreuzotter.de/english/espeed.htm significantly more useful than graphs based on mostly unknown arbitrary assumptions.

I like that calculator and use it a lot, but among its arbitrary assumptions are the limited number of tire choices and surface quality default values. Another speed calculator I use requires you to enter a raw rolling resistance value, so you have to make your own assumptions.

There's a lot of difference in RR between tires in the same size and style category, and even more difference in surface quality. My last cycle tourist house guest noted that chip seal costs him one whole gear interval worth of efficiency, versus regular asphalt pavement.