COUNTER STEERING

Counter steering is the name given to the counter-intuitive technique used by cyclists and motorcyclists to turn corners. It is the only way a rider can cause a single-track vehicle at speed to turn.

It is important to distinguish between counter steering as a physical phenomenon and counter steering as a rider technique for initiating a turn (the usual interpretation of the term). The physical phenomenon always occurs, because there is no other way to cause the bike and rider to lean short of some outside influence such as an opportune side wind, although at low speeds it can be lost or hidden in the minute corrections made to maintain balance. On the other hand, the technique of applying pressure to the handlebars to initiate a turn is not always necessary, since, on a sufficiently light bike (especially a bicycle), turning can also be initiated by shifting body weight. Documented physical experimentation shows that on heavy bikes (many motorcycles) shifting body weight is ineffective at initiating turns.

How it works

When riding a motorcycle, counter steering is a method of initiating a turn by a small, momentary turn of the front wheel, usually via the handlebars, in the opposite (counter) direction. While necessary at all speeds, the need to counter steer becomes more noticeable as speed increases.

A bike can negotiate a curve only when it leans towards the inside of the turn, at an angle appropriate for the velocity and the sharpness of the turn. Otherwise centrifugal force will tip the bike and rider over towards the outside of the curve. The transition of riding in a straight line to negotiating a turn is a process of leaning the bike into the turn.

If a rider wants to turn to the right, he first throws the bike off balance by momentarily pointing the front wheel slightly to the left. The center of mass of the bike plus rider will continue in a straight line, but the contact patches of the tires move to the left with respect to this straight line. As gravity then tips the bike over to the right, the front wheel is steered into the curve, and the curve is negotiated with the proper inward lean. This process usually requires little physical effort, because the geometry of the steering system of most bikes is designed in such a way that the front wheel has a strong tendency to steer in the direction of a lean.

At low speeds counter steering is equally necessary, but the counter steering is then so subtle that it drowns in the continuous corrections that are made in balancing the bike.

Once in a turn, counter steering is again required to make changes to its shape. The only way to decrease the radius at the same speed is to increase the lean angle, and the only way to increase the lean angle, is again to momentarily steer opposite to the direction of the curve. To the untrained, this can be extremely counter-intuitive.

To exit a turn, counter steer by momentarily steering further in the direction of the turn. This tilts the bike back upright.

Counter steering is indispensable for bike steering. Most people are not consciously aware that they employ counter steering when riding their bike. Their body has learned to include the well timed counter steering jolt. They may have learned to do so while learning to ride a bicycle in childhood. Often people simply assume that the steering of a bike is just like the steering of a car. Their subconscious balance skills know better.

As is well-known in bicycle racing, the counter steering phenomenon becomes evident when there is an obstacle preventing the wheel from counter steering, e.g., when closely overlapping wheels or riding very close to a curb. In these situations, the only way to initiate a turn away from the obstacle is to come into contact with it, that is, turn towards the wheel or curb in order to avoid crashing into it. Lack of understanding of this principle leads to accidents in novice bicycle races.

Motorcycles

Even more so than on a bicycle, mastering the technique of counter steering is essential for safe motorcycle riding, and as a result is a large part of the safe riding courses run by the Motorcycle Safety Foundation. At the higher speeds that motorcycles commonly travel at, it becomes increasingly impractical to steer by taking advantage of the minute and random corrections needed to maintain balance.

Much of the art of motorcycle cornering is learning how to effectively "push" the grips into corners and how to maintain proper lean angles through the turn. When the need for a quick swerve to one side suddenly arises in an emergency, it is essential to know, through prior practice, that the handlebars must be deliberately pressed away on that side instead of being pulled. Many accidents result when otherwise experienced riders who have never carefully developed this skill encounter an unexpected obstacle.