There are two main reason scooters are unstable compared to bicycles.
Wheel size. Bigger wheels means more stability over bumps.
Steering angle.
Scooters have a zero degree steering angle (the forks are vertical) which means the smallest turn of the bars leads to a big change in direction and makes them very unstable.
Bikes have forks that are angled away from the vertical. This is much more stable and means that a larger movement is needed to change direction.
Yeah that much, I understand. What I don’t really understand is how that physics actually plays out. Why exactly is a bike’s steering angle able to have that effect?
I guess it’s the difference between knowing and understanding. I know bikes are more stable because of the angle of the forks. But I don’t understand how that works.
To go beyond “The sharper the steering angle the more unstable a bike/scooter becomes” text descriptions you are diving into some pretty heavy theory.
Wikkipedia is a good place to start.
bike dynamics (great article with a lot of details.)
And specifically Trail.
Trail is the term used for steering angle and how it affects stability.
There is a thing called the centering force that is affected by trail. The centering force is the tendency of the wheel to push back to strait when the bars are turned.
There are two main reason scooters are unstable compared to bicycles.
Wheel size. Bigger wheels means more stability over bumps.
Steering angle.
Scooters have a zero degree steering angle (the forks are vertical) which means the smallest turn of the bars leads to a big change in direction and makes them very unstable.
Bikes have forks that are angled away from the vertical. This is much more stable and means that a larger movement is needed to change direction.
Yeah that much, I understand. What I don’t really understand is how that physics actually plays out. Why exactly is a bike’s steering angle able to have that effect?
I guess it’s the difference between knowing and understanding. I know bikes are more stable because of the angle of the forks. But I don’t understand how that works.
To go beyond “The sharper the steering angle the more unstable a bike/scooter becomes” text descriptions you are diving into some pretty heavy theory.
Wikkipedia is a good place to start.
bike dynamics (great article with a lot of details.)
And specifically Trail.
Trail is the term used for steering angle and how it affects stability.
There is a thing called the centering force that is affected by trail. The centering force is the tendency of the wheel to push back to strait when the bars are turned.
The greater the distance between the steering axis intercept and the contact patch, the stronger the centering force becomes.
Hope this helps.