Old 10-11-13 | 01:31 PM
  #41  
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aaronmcd
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Joined: Aug 2013
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From: SF, CA

Bikes: Cervelo S5, Marin Gestalt X11

Originally Posted by Leinster
I know there must be calculated tables for that somewhere. Got a link? I could start reporting some of the suspect Stravas around here...
No link, calculated it.

Air density = 1.15 kPa
Rider weight = 155 lbs (70 kg)
Bike weight 15 lbs
Crr = 0.0033
CdA = 0.35

Hill power = mgv*sin(arctan(grade/100)) = 77*9.8*9.8*0.06 = 444 watts
Wind power = 0.5*rho*Cd*A*(v_relative)^2*v = 0.5*1.15*0.35*9.8^3 = 189 watts
Rolling watts = Crr*mgv = 0.0033*77*9.8*9.8 = 24 watts
Add ~5% for bike efficiency = 0.05(444+189+24) = 33 watts

Total = 690 → 690/70 = 9.9 w/kg

Last edited by aaronmcd; 10-11-13 at 01:46 PM.
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