A spinning wheel on a motorcycle is difficult to turn because of gyroscopic forces. Have you ever wondered why that is and why counter steering is necessary as the speed of the wheels increases? Have you ever wondered how a motocross bike rider can change the plane of a motorcycle in mid air in a seemingly effortless way?

Here’s some thoughts based on a sound understanding of physics and what actually works on a motorcycle which is intended to bring some clarity to our understanding.

Gyroscopic Forces Are More than You Might Think

The difficulty in turning a spinning wheel on a motorcycle is largely due to gyroscopic forces, which are a consequence of a physical principle known as gyroscopic precession.

Here’s a simplified explanation:

1. Gyroscopic Effect:

When a wheel spins, it creates a gyroscopic effect. This effect means that the spinning wheel tends to maintain its orientation in space. The faster the wheel spins, the stronger this gyroscopic effect is.

2. Gyroscopic Precession:

When a force is applied to a spinning wheel, the resulting movement (precession) occurs 90 degrees from the point of applied force.

In the context of a motorcycle, when you try to turn the handlebars (applying a force), the gyroscopic precession of the spinning front wheel makes the wheel want to lean to one side or the other rather than turn directly in the direction you’re steering.

This is why you often see motorcyclists leaning into a turn.

3. Stability and Manoeuvrability:

At higher speeds, the gyroscopic effect of the spinning wheels adds to the stability of the motorcycle, making it easier to stay upright.

However, this same effect makes it harder to quickly change the direction of the motorcycle, as the wheels resist changes to their orientation.

In summary, the gyroscopic forces in a spinning motorcycle wheel create stability but also resist changes in direction, making the wheel more difficult to turn, especially at higher speeds.

Gyroscopic Precession in Simple Terms

Gyroscopic precession is a bit like what happens when you try to change the direction of a spinning top. Imagine you have a top spinning on a table. It’s spinning upright, perfectly balanced.

Now, suppose you gently push the top of the spinning top to the side. Instead of tilting over in the direction you pushed it, the top actually begins to lean and turn at a right angle to where you pushed it.

In simpler terms, when you apply a force to a spinning object, the resulting movement occurs not in the direction of the force, but perpendicular (at a right angle) to it.

This is gyroscopic precession, and it’s a fundamental principle that affects everything from spinning tops to the wheels of a motorcycle.

Gyroscopic Precession and Counter Steering

The question is this – Does this gyroscopic precession have an influence on how effective counter steering is on a motorcycle?

The answer is yes, gyroscopic precession plays a significant role in the effectiveness of counter-steering on a motorcycle.

Counter-steering is the technique used by motorcyclists to initiate a turn. Here’s how it works in relation to gyroscopic precession:

1. Initiating the Turn:

To turn right for example, a rider initially pushes the handlebars so they point slightly to the left (i.e. push on the right side of the handle bar with the right hand), it applies a force to the front wheel.

This might seem counterintuitive, but it’s the essence of counter-steering.

2. Effect of Gyroscopic Precession:

When the rider pushes the handlebars so they turn slightly in any direction, it applies a force to the front wheel.

Due to gyroscopic precession, the effect of this force occurs 90 degrees in the direction of rotation. So in this case where the handlebars are turned slightly to the left, it causes the motorcycle to lean to the right.

3. Completing the Turn:

Continuing the example ..

Once the motorcycle is at a lean and on the line the rider desires to the right, the rider then stops pressing on the handle bar. The gyroscopic effect comes into play and the motorcycle then wants to maintain that direction and hold that lean and line.

The effectiveness of counter-steering is closely tied to the speed of the motorcycle and the rotational speed of the wheels.

Reality is that at low speeds, say pushing the bike, you can steer it in pretty much any way. As speed increases, so does the gyroscopic effect.

At higher speeds, where the gyroscopic effect is stronger, counter-steering becomes more necessary and is the most effective method for initiating turns. Anyone who has ever turned a bike into a corner at over 200 kilometres per hour (e.g. turns 1 and 3 and 8 and 12 at Phillip Island GP Circuit), knows this is the only effective to steer a motorcycle at speed.

Counter Steering is a crucial technique for safely and efficiently manoeuvring a motorcycle, especially at higher speeds.

Watch The Video

We created this video to support this article. In it you will see the Gyroscopic Precession in action.

Author

This article was written by George Lee Sye. To learn more about the correct techniques for motorcycle riding including topics covered in this article, you cannot do any better than checking out, and attending the California Superbike School – https://www.superbikeschool.com.au