How exactly do the different gears on a bike change how easy it is to pedal? And why is it that despite being at the appropriate gear, it is still harder to climb uphill despite the same pedals per minute?

Question

How exactly do the different gears on a bike change how easy it is to pedal? And why is it that despite being at the appropriate gear, it is still harder to climb uphill despite the same pedals per minute?

In: Physics

Answer 1

A very basic answer is when the front gear is very small and the back gear is very big it will take (this is just an example) 5 pedal turns to turn the front to make the back spin once, resulting in more torque/pushing power like what you need going up hill.

Reverse that and you will have more speed because the front is spinning once and the back is spinning 5 times but you sacrifice the torque/pushing power, this is what you would use on a flat surface.