Power calculator

From a very good doc
The Aerodynamics of Human-Powered Land Vehicles
Albert Gross Chester Kyle Douglas Malewicki
drag_chart.jpg


Read the complete doc HERE
Pay attention to the chart on page 6 :
 
hey appreciate that...wow sounds like you guys are into some serious calculations....but i am still stumped..the question revolves around how can i use this for a mid drive calculator...

i.e....let say you got a gng mid drive...say 20 to 1 is final ratio at crank...the motor is 24 volt...3650 rpm....controll allows 21 amps....

potetially motor could run at 175 rpm at crank maybe..more like 150 rpm is max... then it is driven through the bike gears...

lets say...1.3 to 1 first and then seven others going down from a 38 t crank...to 44 cassete to 18 t....

how could i use this for these calculators.. i would like to know the amount of power transferred to the bike wheels...

wouldn't a 1000 watts of power have different speeds and load capacities if geared differently....i just can't figure out the above charsts..but i would love to...i am thanking you guys in advance..bar none this is some pretty cool techinical stuff...the reason i am asking is i am trying to figure out what gearing i need in order to use a 24 volt motor...i know crazy but hey this is what we do here.

200 pound man 50 pound bike 250 for it all lets say...pounds...different inclines 2 and 4 and 6 and 8 and 10 and 12 percent......final speed would be interesting..i guesse as long as rpm is running around 50 to 90 percent would be cool.
 
okay went to the thread and omg i was amazed...you must go to the end to get the updated version and man it is awesome.....you guys are really helpful and really smart.......thank you.
 
Okay, time to interject here.

There's a minimum amount of energy needed to climb a hill.
Then there's the minimum amount of energy to push away air molecules at a given speed.

Energy to climb hill = The sum of both of those.

So, yes, speed matters, but there's going to be a minimum amount of energy necessary to lift weight up a hill, regardless if you're going 0.1 mph. Tall hill+lots weight = the minimum is going to be A LOT of energy.
 
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