What is the resion behind that bike get balanced in running condition but get falls in steady condition?

Question

What is the resion behind that bike get balanced in running condition but get falls in steady condition?

Answer 1

I've seen this discussed ad nauseum in other places. But the consensus is, gyroscopic action does not come close to keeping a bike up. Mostly, it's a result of the geometry. As a rolling bike starts to fall, the front wheel turns in the direction of the fall. The term is "fork flop." But it goes into the fall faster than the rest of the bike. This causes it to steer past the fall and overbalance in the other direction, which makes the bike start to fall in the *other* direction. The bike continues to wobble, self-correcting itself as it goes, until it slows so much that it can no longer self-correct. How well it does this and at what speed it does it best, depends on the steering angle ,fork rake, and trail. Head tube lift enters into it, too - the head tube is lower when riding straight ahead, and higher when the steering is turned. This means the bike works against gravity to turn, so the steering always tries to return to center if it can.

It's been said that a rider has 2 functions: 1, to provide power, and 2, to unbalance the bike so that it can be turned in the desired direction instead of straight.

Answer 2

It's the gyroscopic action, as MR stated. Think about rolling a penny, the faster it goes the more stable it is.

Answer 3

The gyro action helps, but its not enough by itself.  The subtle interaction of rider and steering is what does it.

Answer 4

.... what?

Answer 5

If I read your question right the answer is the gyroscopic action of the wheels spinning keep the bike balanced. The faster the wheels spin the more stable the bike.