Short · Machines
Why is a low gear easier on a hill?
A road bike's 34-tooth front ring and 34-tooth rear cog turn the wheel once per pedal turn. Shift to 50/11 and the wheel turns 4.55 times, but the same road force needs 4.5 times the foot force.
Try it yourself
Opens Gear Lab. Change the same thing yourself.
Transcript
Why is a low gear easier on a hill? Gears trade speed for force. In a road bike's lowest gear, one turn of the pedals turns the back wheel about once. Now shift up. The same pedal turn spins the wheel more than four times, so you go faster. But to push the bike just as hard, your foot must push more than four times harder. On a hill, you want the opposite. Lots of light pushes instead of a few hard ones. Follow to see how the world works.