Question

How does the speed ratio change as you switch between different gears on a bicycle, and how does this affect the force you need to pedal the bicycle?

Answer 1

An average cyclist generates about 183 watts while doing 19 mph or 30.4 kph. Power = force × velocity. Force of a pedalling applied by a human for achieving 30.4 kph = 183/8.44 = 21.68 newtons. This is for upright bicycles.