Drivetrain Efficiency Summary

Reiterating the Key Drivetrain Result

We have covered a lot of ground in coming to one of the most striking of our conclusions concerning cycling. With the exception of a small loss due to friction, the cycle drivetrain converts all of the power generated by the cyclist into CyclingPower which moves the cyclist-cycle forward.

What it means in evaluating cycling scenarios

What does this mean when we get to analyzing cycling scenarios? Once we have computed the average power required to ride the scenario from the perspective of the cyclist-cycle, we will then look to decide what range of options will provide PedalingPower that is only slightly higher than that forward motion power requirement.

Why Doesn’t Power Depend on Gearing?

I know I was surprised to find Force Transfer was dependent on gearing and yet Power Transfer was not. There is a simple explanation for that. Cycling Power is the product of the force times the distance traveled. So even though the Rear Tire Force is smaller than Pedal Force, it makes up for it by rotating a large tire which covers more distance.

Think of it this way. What needed to happen was the product of Pedal Force times Pedal Speed would be equal to the transformed Forward Force times the tire speed. And given the bicycle design, that is how it works out.

Next Topic:   Cycle Forward Motion