Yet Another Bike Calculator

xyster

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Another interesting, shareware bicycle calculator:
http://www.machinehead-software.co.uk/bike/power/bicycle_power_calculator.html

Fired-up Virtual PC to try it on my mac....
 

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Looks interesting, I'll have to give that one a try. 782W and 35mph sounds pretty streamlined... sounds like someone tucked behind a fairing.
 
I downloaded the calculators and they are nice to have. One simple thing to do is to try lowering the frontal area by as much as you would expect for someone who's legs are missing compared to a "conventional" head down cyclist. The number they begin with for frontal area is 0.3 square meters. Just by changing that to 0.2 square meters you get an enormous improvement. Also they are showing 0.9 for the drag coefficicnt which is roughly equal to a CUBE shape. By going from "cube" to "half sphere" you can drop that to 0.5. This was all the basis of the "Gravity Bikes" and we actually raced some pedalling cyclists with our bikes and could beat them on the downhill without doing any work at all.

:arrow: An electric bike combined with gears and streamlining and a tuck position is amazing when you run the numbers on it.

The only limiitation for me in using these calculators exclusively (over my home grown spreadsheets) is that they don't model the electric part of the equation. For me to get numbers that are any good I need to have the motors powerband and it's performance "issues" included. What a great tool that would be however. As a former computer programmer I could see writing one of these applications and tailoring it for the electric bicycle. You could enter in the Voltage Constant and Resistance Constant and a bunch of other things and run all kinds of simulations to see how the gearing could be optimized. And then end up giving it away for free... :wink:
 
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