How come when you are on a bike you only tip over when it isn't moving?

Question

But when you are moving you stay straight up?

Answer 1

"Experimentation and mathematical analysis have shown that a bike stays upright when it is steered to keep its center of mass over its wheels. This steering is usually supplied by a rider, or in certain circumstances by the bike itself. Long-standing hypotheses and claims that gyroscopic effect is the main stabilizing force have been discredited."

Answer 2

The gyroscopic effect of the rotating wheel "wants" the wheel to stay in the same orientation.  If that's vertical (and I HOPE it is if you are riding your bike), then it "wants" to stay vertical.  A stronger outside force must come along to change that, such as getting bumped by another bike or crashing into something.

Like PeeWee Hermann said, "I meant to do that!"

Answer 3

You can exercise more control over the front wheel direction when moving, and the rest of the bike simply follows the front wheel. There is also an air flow on both sides of the bike which helps keep you upright when the bike is in motion.

Answer 4

The earth is revolving. As you ride a bike, you revolve with it. If you stop, it will revolve without you.

http://www.exmormon.org/pattern/nature.h...

Other vehicles don't respond similarly, due to their being insured.

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Answer 5

If you are moving fast enough, you'll tip over just as easily.

Answer 6

Have you ever ridden a bike? That statement in your question is just fundamentally incorrect.

You are probably asking about the tendency to stay upright.

This is due to gyroscopic force vis a via the spinning of the wheels.

Answer 7

because there is no balance

Answer 8

there is not ummm what do you call it, inertia or momentum.  when your are moving there is a force or energy that propel you in a forward direction. that is what keeps you upstraight. the reason you dont fall is since you have a force in one direction which is forward, its takes a lot of energy/force to change the direction, that is why you dont tip. when you slow down or come to a stop, the forward motion that keeps you up is no longer there.  i guess you can say the force of the earths atmosphere and your mass comes into play.  whatever side you weigh more on, your going to tip in those direction.  

Answer 9

The wheels become gyroscopes which keep you upright at a 90 degree angle to their axis.

The faster the wheels turn the harder it is to turn them from their rotational axis.

Answer 10

Great answers so far!  The correct answer is the "Conservation of Angular Momentum Law", often called the gyroscopic effect.  (The angular version of Newton's First Law of Motion.)  A force is required to lean a wheel spinning about it's axis.  

Bonus point:  If you are going fast enough and want to turn left, you actually turn the handlebars just a little bit to the right, which causes the bike to lean to the left.  This is called "countersteering", but is the same principle at work.

Answer 11

If it were gyroscopic forces that kept the bike upright, then precession would keep you from riding in a straight line. In reality, you balance by steering the bike through and past the center of gravity. Or to put it another way, the bike is always falling, but by steering into the fall, you overbalance the other way, initiating a fall in the opposite direction, at which point the process starts all over again. A good cyclist can minimize the amount of zig-zag, but the fact is, without being able to steer back and forth a bike cannot be balanced.

Depending on the geometry of the bike, turning the steering causes the head tube to raise and lower, which affects the 'rest' state of the steering. If the geometry is good for stability, then the amount and direction of head tube rise causes the bike to fall the same way and rate as if it were steered by a rider - within a range of speeds. That's why you can roll a bike down a hill and it will balance itself as long as it's moving at greater than its balance speed.But eventually wheel flop becomes too great compared to head tube lift and the bike tips over.

Answer 12

Because you're bike is a victim to gravity.

Answer 13

It's due to magic worms that live in your tyres!

They prefer to return to muddy earth, if they spin, it disorientates them but when you slow down or stop they shift their weight towards the ground and you fall over!  - It's a well known fact!

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Answer 14

It's actually a thing even physicists can't get their head around...

As far as I know. :)

Answer 15

because the gyroscopic force of the wheels keeps them upright.  Try this test... take a bike wheel or something with an axle and hold both sides of the wheel in your hands and spin it.  while it is spinning, it is hard to tilt it.

Answer 16

instead of having two thing one in back and front that are skinny... we have these things called feet which are bigger that wheel tires and they are on each side not front and back

Answer 17

centrifugal forces are at work when you cycle.

Answer 18

When you are not in motion it is harder to stay straight up when riding a bike.  It is just a law of physics. Forward motion creates pressure on both sides of you that keep you up.