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Q & A: Peddling a bike uphill

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Most recent answer: 11/04/2011
We're having a debate here about bicycle weight vs. wheel weight vs. human weight. Assuming two cyclists are pedaling up a 7% grade at the same wattage and both weigh 150 pounds what is the weight differential as far as a bike and its components go? The idea is that for every pound of rotation on a wheel it translates to 5 pounds on the actual bike as well as 5 pounds on the person itself. Simply put its a 1:5:5 ration for bike wheel to bike frame to person. Keep in mind this is at a 7% grade. What do you guys think?
- Nicholas Kane (age 23)
If you neglect the opposing frictional forces, which you really can't, the energy input is Watts times time. The energy gained in going uphill is MgH where M is the total mass, person, plus bike frame plus wheels, g is the acceleration of gravity and H is the difference in elevation.   Big wheels versus little wheels doesn't make any difference, it's the total mass that counts.


Right- The mass on the wheels counts extra when you're asking how hard it is to accelerate, not how hard it is to go uphill.  Mike W.

(published on 11/04/2011)

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