Bicycle Power Calculator

This is just amazing.

http://www.mne.psu.edu/lamancusa/ProdDiss/Bicycle/BIKEcalc1.HTM

Bicycle Power Calculator

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Assumptions:
Constant speed analysis
Drag coefficients reference "Science of Cycling", E.R. Burke, Leisure Press, 1986, pg 126.

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Inputs
Wheel Diameter (inches) Crank Length (inches)
Desired Constant Speed (mph) Rider's Weight (lbs) Bicycle Weight (lbs)
% Grade (+ for uphill,- for downhill) Mechanical Losses (3-5% is typical) %
Gear Ratio (#Teeth Rear/Front) 1.00 (28/28) Slowest .872 (34/39) .718 (28/39) .615 (24/39) .512 (20/39) .435 (17/39) .359 (14/39) .654 (34/52) .538 (28/52) .461 (24/52) .385 (20/52) .327 (17/52) .269 (14/52) .200 (11/55) Fastest
Air Resistance Coefficient (lbf*s^2/ft^2) = Cd*FrontalArea (Cd*A =.0044) Straight Arms (Cd*A =.004) (Cd*A =.0036) Full Crouch (Cd*A =.0032) (Cd*A =.003) Hill Descent (Cd*A =.0027) No Rider (Cd*A=.0012) Zero Air Drag (Cd*A=0)
Rolling Resistance Coefficient (lbf/lbf) .013 (27x2.25" 45 psi BMX Knobby Tires) .010 .007 .004 (27x1.125" 95 psi Road Clinchers Racing Tires) 0.00 (Zero Rolling Resistance)

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Calculated Outputs
Total required input power from the rider HP Watts
Power needed to overcome air resistance HP %
Power to overcome rolling resistance in tires HP %
Power needed for elevation change HP %
Power lost to mechanical losses, friction, etc. HP %
Calories burned per mile kcals (assuming 28% efficiency in conversion to human power output)
Average Pedal Force Lbs Average Traction Force Lbs
Pedal Speed RPM Tire Speed RPM

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You are visitor # since 14 March 2005

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copyright 1999 Penn State 19 August 2005 by John S. Lamancusa - Penn State University (jsl3@psu.edu)
Accuracy checked by ME288 Product Dissection class, Underlying Equations
Modified to work with Netscape 4.0 by Matt Lindenberg

Go to Product Dissection Homepage

Other Calculator sites

http://www.machinehead-software.co.uk/bike/power/bicycle_power_calculator.html

http://www.noping.net/english/

http://bicycle-power-calculator.10001downloads.com/download