Why do different gear ratios give different torque? Why isn’t it the faster a wheel goes the more torque it has?

Question

Why do different gear ratios give different torque? Why isn’t it the faster a wheel goes the more torque it has?

In: Engineering

Answer 1

A higher RPM in an easier gear ratio can equal the power output of a lower RPM in a harder gear ratio.

This is because power output = torque x RPM.

You can test this yourself using a bicycle. Put the bike in an easy gear and spin your legs at 60rpm. Then put your bike in a hard gear and spin your legs at 60rpm. You’ll find that in the harder gear you went faster – increased power for the same RPM. You’ll also notice a much greater muscular strain. What you’re feeling there is the increased torque required to turn over the gear.