Inputs
Wheel Diameter (inches)         Crank Length (inches)
Desired Constant Speed (mph)       Rider's 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) Straight Arms (Cd*A =.004) Full Crouch (Cd*A =.0032) 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)

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
    Average Pedal Force Lbs     Average Traction Force Lbs
    Pedal Speed RPM                Tire Speed RPM

Acknowledgements

These materials are based upon a course presented by the University of Washington developed under the Manufacturing and Engineering Education Partnership.  The intent of this partnership is to develop new educational programs and to facilitate the free dissemination of these materials, thereby saving other institutions the expense and time of similar developments.  Accordingly, all materials for this course may be freely copied and edited as desired.