Friday, July 23, 2010

65 mph wind test

Note: In this study, the bike still went a good 9 miles at urban speeds after it lost the power to go 65 mph. 

I remember when I was a kid my dad told me the freeway speed limit was increased from 55 to 65mph because the state politicians wanted more money to make the budget look better and knew how much that 10mph would increase gas consumption due to wind resistance inefficiencies of most automobiles (note I've never taken the time to verify how much fuel tax revenue did increase after raising the speed limit).  As anyone who has tried cycling or taking a motorcycle say 100mph knows how strong wind resistance is and how much wind resistance hinders your speed exponentially (or something like that) the faster you go. With all that, I still was not sure how much wind resistance was affecting my Zero Millage.  Motorcycles are so much more aerodynamic than a car I have never noticed much of a difference when changing speed from 55 to 65 mph on my sport bikes (but there is a huge difference between 90 and 65 mph). On my sport bikes, over long freeway drives at around 70mph I have definitely noticed better gas millage when tucked under the windscreen compared to siting up straight, however it is a small enough percentage, 10% at best, I had never exactly quantified it.  

65mph wind resistance test:  I completed the same ride in two riding positions to compare the wind resistance influence on this vehicle.  I wanted to know if wind resistance was a factor when determining how long I could travel at the faster speeds.  I wanted to ensure I was making accurate data comparison by knowing the affect of my riding position.   Both rides consisted of trying to keep the bike as close to 65mph as possible, but had speed ranges from 60-67 in addition to at least two stopping points for the shorter distance. 

Tucked: I managed to ride this dirt bike style machine like a wanna-be road racer, trying to get my body as tucked as possible reducing the wind resistance my body would have on the bike. I made it 23.3 miles before the slightest loss of power took the bike down to top speed of 62 mph.  

Dirt bike style: On the second ride I wore my full gear and stat up as straight as possible, to make as much wind drag as my body could make. I maintained approximately the same speeds.  The millage was 50% less!. Down to 11.8 miles until the first reduced power.  Once again keep in mind the bike still effortlessly completed another 9 miles at speeds ranging from 40-55 mph. 

Moral of the story the model of the Zero being used to race the TTXGP this year (pictured above) may have much better millage (think 2 times better) at freeway speeds compared to the dirt bike inspired model.

1 comment:

  1. Good test! I like the myth busters approach.