Re: E-Bike drag coefficient

[Ben Haines <b.haines@student.unsw.edu.au>]

The equation you need is

Power at ground = mgCrrV + 1/2CdApV^3
m = Mass Kg
g = Gravity  9.8m/s^2
Crr = Rolling coefficent
V = Velocity M/s
Cd = Drag Coefficent
A = frontal area
OR
p = desity of air 1.2Kg/m^3


this is for flat ground with no wind

Ben


At 12:02 PM 6/26/01 -0700, you wrote:
>All,
>   I am trying to calculate my required horsepower to run 60
>mph on my E-bike. I have the rolling resistance of 0.018,
>which is listed as common resistance on concrete(is this
>too much?), but have no idea what to expect for wind drag.
>   The bike will be unfaired, but also relatively small,
>with no huge massive windscreen. The style will be
>sport-bike, so i wont be bolt upright like a sail. I could
>tuck in too, if needed. What should i expect for drag?
>Without drag i calculated 1.5 hp to propel me&bike(480 lbs)
>at 60mph. This seems easy to do with a golf cart motor, but
>the drag will kill me i bet.
>
>=====
>Jim Weir
>
>1974 Z1                 1980 CB400t
>1989 KX125              2001 Electric Mini-Bike
>2001 SemCycle XL Uni    2001 Coasting Unicycle
>http://www.geocities.com/skullfracture/YSRkid.html
>
>__________________________________________________
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From: Ben Haines
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