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Why Do Racing Motorcycles Lean So Much? It’s Physics
This is a story about angular momentum. I’ll be honest, angular momentum is cool and everything but it’s one of the more difficult concepts to explain from scratch. Unfortunately, there a bunch of great real world examples that use angular momentum — so we are going to have to just jump into it.
In this case, we are going to look at racing motorcycles. If you’ve ever seen one of these races, they lean VERY far during the turns. Why? How? Yes, we are going to get to this.
Leaning Bicycle
If you want to get into motorcycles, you should start with a bicycle. The same is true with physics. Let’s consider a bike taking a turn. Here are two diagrams. Both sketches are for a cyclist turning to your left and pointing out of the screen (just in case my stick figures aren’t clear). The left diagram is just a picture of a cyclist. On the right I am representing the bike and person as just a stick. In this case I can show the three forces acting on the system.
The three forces in this case are:
- The downward gravitational force (mg) acting at the center of mass for the rider-bike system.
