How Does a Bicycle Stay Upright?
If you get on a bicycle and start pedalling, what do you feel?
You will feel the movement of the bicycle, as you move forward.
Doesn't it fill you with surprise that you can move forward on two wheels, just by pedalling
your way?
Let's see what happens when a stationary bicycle is pushed without a rider.
Oh, look!
The pushed bicycle keeps moving.
It's becoming slower and now it has fallen!
Oh!
No!
A moving bicycle will continue to stay upright and move forward because of momentum, till
it falls down because of gravity.
Did you know that till a few decades back, scientists thought a bicycle stays upright
because of the Gyroscopic Effect.
The Gyroscopic Effect means that a spinning wheel tends to stay aligned in its original
direction, during momentum.
This is known as Angular Momentum or spinning action.
So, if it is not the Gyroscopic Effect, what actually keeps the bicycle upright?
The scientists who study bicycles, experimented a bit more to discover, that if the gyroscopic
effect were to be cancelled, the bicycle would continue to be upright!
So, they assumed, it must be the caster effect of the wheels.
Because the bicycle wheels are attached to a centre axis on a frame to help them rotate.
What is the caster effect's role in keeping bicycles upright?
If you look at a bicycle, you will see that it is designed in such a way, that the front
wheel's steering axis makes the front wheel move faster than the back wheel.
So, when the bicycle starts moving to the left, the Centrifugal Force of the back wheel
would keep it in check, because it is still moving straight.
The wheel would automatically snap the bike to the right and keep it upright!
So, now you know, that Angular Momentum and Centrifugal Force keeps a bicycle upright
when it is moving.