The Art Of Safe Riding

All motorcycles are built to be inherently stable i.e. they will tend to travel in a straight line if undisturbed. Even if they are disturbed by a slight turn of the handlebar, they will tend to return to the straight and upright position. This is made possible by the geometry of the motorcycle’s construction. The front wheel is inclined forwards at an angle (called the ‘Rake’). The front tyre’s contact patch falls below the front-wheel’s axle while a line extending and following the Rake angle meets the ground a little further ahead of the contact patch. This distance between the contact patch and the extended rake line is called Trail. Trail is primarily responsible for a bike’s straight line stability. Of course too much stability (vis-à-vis a large trail as in cruisers for example) leads to sluggish maneuverability. Motorcycle design is therefore always based on the targeted end use of the bike.



At very slow speeds we steer a motorcycle by turning the handlebar in the direction we wish to go. We can only do that at speeds of less than about 10kmph. At any higher speed, we do the exact opposite, whether we realize it or not. For example, assuming we want to turn to the right, we actually TRY to turn the handlebar left. This results in the front wheel leaning to the right and, as a result of the lean of the wheel, a turn to the right. This is counter-steering. No matter how slight, if your front wheel deviates from a straight path your motorcycle will begin to lean in the opposite direction. You can observe it at a complete stop. Just turn your handlebars in one direction and you will see that your bike leans in the opposite direction as a result. The ONLY WAY to turn a motorcycle that is moving faster than you can walk is by leaning it.

There is another, more powerful, reason that the lean is translated into a turn - Camber Thrust. Unlike car tires, your motorcycle rides on tires that are rounded instead of flat from side to side. When you are riding vertically the contact patch is right in the middle of the tire, at its farthest point from the hub of the wheel. When you are leaning, you are riding on a part of the tyre that is closer to the hub of the wheel. The farthest parts of the tyre from the hub of the wheel are TURNING FASTER than any part closer to that hub. Thus, when you are leaning, the outside edge of the contact patch is moving faster than is the inside edge. To make it easier to understand this, imagine a typical motorcycle tyre profile as two truncated cones joined at their bigger flat faces. As the tyre leans to one side, just one cone comes into contact with the road. And as the bigger end of the cone lies towards the outside of the turn and the smaller end towards the inside, the outside edge Your browser may not support display of this image. has to travel a longer radius and so travels faster than the smaller end thus making the cone (and so the tyre) follow a circular track.



Counter-steering is a much more effective way to steer a motorcycle than shifting body weight. If something suddenly enters your path and there is no way to stop in time, counter-steering may save your life. The trick is to look past the object to your escape route, and to quickly counter-steer in the proper direction. Imagine yourself cruising down the highway on a beautiful bright day. Suddenly you see (your worst nightmare: a large pothole, a dog, a rock or whatever) in the road, covering the right two-thirds of your lane. If you do not consciously understand and use counter-steering, you will probably attempt to steer left like you would on a slow moving bicycle or in a car where you steer left to go left. To do that you will push on the right side of your handlebar and this will steer you directly into the object. The correct action here would be to push on the left side of the bar (as if you are steering to the right i.e. towards the obstacle instead of away from it) and steer away from the obstacle. That is why we call it counter-steering (since we steer in a direction counter to what we feel is the normal one). So remember: "Push left to turn left. Push right to turn right." (see figure below) Like any safety technique, it only works if you practice it. Unless the action is second nature, you will return to your old habits during an emergency. Riders who do not practice counter-steering, will try to turn away from the object, which just brings them closer to it!

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rajesh1136

Sorry if it is a silly doubt... im not understanding it...

see yesterday i skid and fell . reason.. one lady crossed in middle of the road.

she approached from right and if i have to escape i have some space in the left side of the road. which even i tried but couldnt do it. panicked and applied brakes which made me to fall down

my question.. if you push right obviously the wheel will turn to left and my bike will go left...

how it will go right if i push right... may be if i pull from left the bike will turn left.

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'Santa

Thats the common logic. However, Counter-steering, as explained above, is very much a reality and easy to execute. Give it a try on a clear stretch of road, you'll know for yourself!

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indian07_blood

counter steering is something you can't understand in theory. The same phenomena is experienced by us in our daily biking dose but still most of the bikers are unaware of it. Counter-steering is experienced at a high speed because of which the bike leans. At low speed say like 40kmph the effect will be really low and you couldn't tell if you are on it. Take your bike around 60km/h on a fine day with clear road and try to push the left handle bar. You will see the bike starts leaning to the left and moving to the left, the vice-versa is also true. It is directly propositional to the speed.

Try It, Learn IT and RIDE SAFE.... :-)

Regards,
Shantonil

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sanchit223

Sorry about your accident, I hope you are all right.

You should try to lean towards the turn to turn faster while counter-steering. (Counter-steering essentially makes the whole bike lean, so it helps if you yourself shift your weight a bit towards the turn, check MotoGP)

When riding a bicycle or 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. This moves the pivot point (the wheels' contact patches) out from under the center of mass to establish the lean angle for a turn. While necessary at all speeds, the need to counter-steer becomes more noticeable as speed increases.

Hence, to turn to the right, the rider 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 the desired angle is approached, the front wheel must then be steered into the turn to maintain that angle or the bike will continue to lean with gravity, increasing in rate, until the side contacts the ground. 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.

The actual torque the rider must apply to the handlebars in order to maintain a steady-state turn is a complex function of bike geometry, mass distribution, rider position, turn radius, and forward speed. At low speeds, the steering torque necessary from the rider is usually negative, that is opposite the direction of the turn, even when the steering angle is in the direction of the turn. At higher speeds, the direction of the necessary input torque often becomes positive, that is in the same direction as the turn.
Source: Wikipedia, Our Mighty Saviour


Maybe these two videos will help you understand counter-steering better. The first one explains the theory and the second one (fast forward to about 2:20 min) is just a demo.

TenHut

nope..its different for motorcycles. Any two wheels..even the bicycles...
the best advice is to try it. Wear gear..go slow. At any speed above 30kmph slightly push your bar with your right hand(motioning the handle bar to left). You will lean to right and start turning right.

If you are riding a motorcycle you are already doing it. Its just that you are doing it unknowingly. Doing it knowingly changes your riding drastically and you start improving by leaps and bounds.

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niaz_be

Correct me if I am wrong. The trail is the distance between the steering stem/neck axis and axis of the forks. The diagram doesnt show any steering axis.

satya_3d

no, trail is the distance between points on ground plane; where steering axis meets ground and verticle line passing through contact point of front wheel. the above diagram shows it correctly.

cruiser bikes(avenger, enticer) has more trail than sport bikes (pulsar, karizma). change in trail value can affect steering (cornering), stright line stability, braking ability of bike. for more technical info try getting motorcycle dynamics book by vittore-cossaltire (not sure about authors name spelling, sorry)
cheers..

avinrichards

^^Hey.. either ways... both the angles are same right ? I mean.. by geometry rules and stuff.

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gautam_k

how come? the line that you traced(steering axis) and the line in the first post are always parallel right? if yes, then the rake angle shouldn't differ, only the trail length should differ.

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