Caster angle in bikes / cars - Why do we need?

[k.udhay]

Hi,

What is the purpose of having a caster angle / "trainling" in a bicycle or bike? Many websites say it is for stability. But how does this angle improve the stability? What if I have my front fork perperndicular to the ground? What and why are the consequences occur?

Thanks.

 

[jedishrfu]

Then you have a greater chance of going over the handlebars when braking.

Bicycle physics is very hard stuff. Wikipedia has an artile on it that may help:

http://en.wikipedia.org/wiki/Bicycle_and_motorcycle_dynamics

People used to believe that the gyroscopic motion of the spinning wheels contributed to its stability but that was found to be not correct. More recently someone discovered that caster angles aren't necessary either. The wiki page describes some of the history of bicycle physics analysis with references to other articles.

 

[k.udhay]

Thanks, Jedishrfu. It's pretty hard to believe that "More recently someone discovered that caster angles aren't necessary either"...
I think it is some real interesting stuff, as everytime I try to understand it confuses me a different way... :)