You need to ride more.

 

 

A simple and fun experiment that can be performed with a standard bike involves the use of a rocket. The strategy is to affix a small model rocket onto a handlebar to one side. The intent is that the bike will be pushed forward without rider, and the rocket will be ignited by remote means or by a timer or delay of some sort. When a bike is pushed off in a straight running line, and the rocket ignites, a steer torque is applied to the handlebars. The astonishing result is that the bike does not steer in the direction of the steer torque, but rather in the opposite direction. This astounding fact perplexes many onlookers. In essence, the bike turns in the direction opposite to the applied steer torque. This experiment demonstrates conclusively that the bicycle’s dynamic behavior is counter-intuitive from the perspective of handlebar steering actions.


Even skilled and proficient bike riders are often puzzled by the results of this experiment. The explanation lies in the fact that the rocket creates a steer torque which, yes, momentarily turns the handlebars in the direction as pushed by the rocket. This steering action in turn causes the base of the bicycle to steer in that direction. But now the bike has been forced into a lean because the ground contact support points have shifted by steering action or offset to one side, and – a lean away from the steer direction then results. It is this reversed direction lean, combined with the front fork geometry involving head angle, rake, and trail, which overpowers the rocket force and turns the bike’s handlebars into the direction of the lean – and opposite to the direction of the applied rocket torque.

In engineering terms we say that the bicycle exhibits counter-intuitive behavior. We can mathematically say, using the language of systems theoretic principles, that the bicycle exhibits “non-minimum phase behavior.”
The significance of the bicycle’s non-minimum phase behavior is that the bicycle usually does the opposite of what the intuitive mind would and might expect. As an example, if we want to steer right using handlebar actions as opposed to leaning, we actually steer first in the opposite direction, or to the left. Accident studies show that nontrivial numbers of motorcycle deaths occur in the case of less experienced riders – as when an obstacle or danger appears, the intuitive reaction is to steer away. But, in doing so the motorcycle sets up a lean towards the obstacle and the motorcycle invariantly impacts the object – and hence a serious collision results.

The proper emergency steering action is called “counter-steering,” whereby the skilled rider initiates a turn by turning towards the hazard. This action sets up a lean away from the hazard, and thus the rider can thereafter quickly and safely turn away from the hazard as a proper lean has been established. In addition, skilled motorcyclists will combine this action with an upper torso lean away from the hazard, in that sense “intuitive,” so as to as efficiently as possible extricate themselves from the hazardous circumstance.

 

Agreed, we all need to ride more!

 

Everyone's experiences while riding are different. But, the physics of riding do not change.

 

It's called "gravity".

 

This is what I am talking about. If I had asked you what caused my problem, years ago, you would have "gravity".

But what really caused my crash was grabbing the front brake when the front wheel was turned at slow speed.

Here is something to lighten the mood.

 

Are you saying gravity had nothing to do with it?

 

I am saying that your answer shows a definite lack of attention to detail.

The "Read More Drive Less" quote was directed specifically at you, no one else.

 

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