Cycling Power and Speed Calculator

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Revision as of 17:53, 29 January 2019 by Marcin (talk | contribs) (→‎Notes)
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Solar vehicle version, 8'x16' body - so 1000W of solar panels.

This would go at 25 mph with a 300 lb vehicle weight, 165 lb rider weight, with 5 square foot frontal area with 500W of power according to this calculator -

https://www.gribble.org/cycling/power_v_speed.html

Example

High Speed

  • Drag coefficient of 0.1 from an airfoil type body
  • Vehicle 300 lb, rider 165 lb
  • 150W of leg power
  • Frontal area of 8 square feet
  • Crr = 0.1 for mountain bike tires
  • 1000W gives 50 mph -realistic but best case scenario
  • Adding more length at back gets more power, no more drag
  • Thus, a practical car can be made, esp if it has batteries or small generator (1kW) for extra power.

Low Speed

  • Same parameters as above, 500W of power - gets you 35 mph

Notes

  • Biggest gain is obtained from reducing coefficient of drag due to wind. Air foil (wing) has the lowest drag - less than 0.1
  • Best cars are at cd=0.22 - [1], and VW XL1 cd=0.19 [2]. Impractical cars can do better.
  • Aptera - lowest cd=0.15 in history for a production car[3], which is 850 mpg equivalent.
  • Stingray/Stealth bomber/airfoil mix type bodies can be around 0.1

Links