It seems like moving forward would just be another factor making balancing more difficult.
2006-08-02 14:52:35 · 7 answers · asked by The Ghetto David Hume 3 in Science & Mathematics ➔ Physics
The spinning or gyroscopic motion of the wheels has nothing much to do with it. The wheels could be replaced by non-spinning runners (e.g. ice skating blades) and the technique of balancing would be about the same.
When the bike is in forward motion and starts to tip (say) to the right, the rider turns the front wheel slightly toward the right. The bottoms of the wheels are pulled to the right but the inertia of the rider and bike is in the forward direction. It's just like jerking the bottom of the wheels to the right so that they're back under the center of mass of the rider.
An equivalent way of looking at it is that turning the wheel right creates a temporary rightward curving path which causes a leftward centrifugal force in the moving (non-inertial) frame of the bike and rider. In the moving frame, this causes the top of the bike and rider to pivot leftward.
This technique works because the action of turning the wheel to the right or left causes an immediate force in the correct direction (i.e. opposite to the direction of the turn) and the force can be stopped or reversed just as immediately by straightening the wheel.
Now compare that to trying to balance on a bike which is standing still: If it starts to fall to the right, the only way to prevent it is to move some weight (e.g. the upper part of the body) to the left. The only problem is that the process requires temporarily exerting a rightward force on the bike to compensate for the leftward force on the mass being put into motion. In other words the immediate effect of this action is to generate a force in the exactly wrong direction. That's why it's almost impossible to sit on a bike standing still and not fall.
2006-08-06 11:08:39 · answer #1 · answered by shimrod 4 · 1⤊ 0⤋
At higher speeds, the gyroscopic effect gets big enough to make a difference. But at slow speeds, the forward motion makes balancing easier because it gives you the ability to move the center of gravity from the bottom, rather than from the center of gravity. THAT'S hard!
2006-08-02 15:25:37 · answer #2 · answered by Anonymous · 0⤊ 0⤋
I think Mark's on the right track but I believe its called gyroscopic force. The resultant of rotational momentum, the wheels spinning, acts at 90 degrees to the direction of rotation. I've seen experiments where the victim holds a spinning bicycle wheel and tries to tilt it over it requires a unexpected amount of force.
Two wheeled vechicals stablility increases with speed.
2006-08-02 15:11:38 · answer #3 · answered by Roadkill 6 · 0⤊ 0⤋
The centrifugal force of the wheel "helps" maintain the balance. Take the wheel of the bike, spin it and you can hold just one side of the axel and it will stay on your hand....and it will rotate one way or the other depending on which way it was spun. PS...you can also balance on your bike if you ride it backwards- by the same principal.
2006-08-02 14:58:53 · answer #4 · answered by Mark H 1 · 0⤊ 0⤋
A bike can be balanced when it's center of gravity is over its wheels. Forward inertia makes it easier because it can keep you upright while you unconsciously adjust. Just keep pedaling!
2006-08-02 14:58:13 · answer #5 · answered by ritifo 2 · 0⤊ 0⤋
Momentum counter acts against gravity
moving weather forward or backward
takes away form the gravitational pull side to side
2006-08-02 15:02:41 · answer #6 · answered by jayredd007 1 · 0⤊ 0⤋
momentum keeps you upright and going forward
2006-08-02 14:56:23 · answer #7 · answered by Kalahari_Surfer 5 · 0⤊ 0⤋