Talk:Countersteering

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Contents 1 Definition 2 Text from counter-steering article 3 steering geometry 4 Contradiction 5 Angle vs Camber Angle 6 Language 7 Walking speed 8 Better not give two different explanations for one thing 9 Gyroscopic effects 10 Very low speed

[edit] Definition

You push in the direction you want to turn. The "counter" part refers to the fact that you are actually turning the handlebar in the opposite direction when you do that, so that is probably what is was intended to say by that change that was made. I remember from the Motorcycle Safety Foundation course that pushing in the direction you want to turn makes it more intuitive and therefore easier to remember. I have corrected the article back to my original and merged counter-steering into this article.Spalding 04:13, Dec 8, 2004 (UTC)

I don't think the cleanup tag is justified - between my explanation and the external link, I think it is clearly and logically explained. Spalding 17:10, Feb 4, 2005 (UTC)

[edit] Text from counter-steering article

The following text from User:Manning Bartlett has been copied from the counter-steering article to merge it into this article:

I sat down with all good intentions of writing this article. But as soon as I began to research the various web-pages, I quickly realised that I was out of my depth physics wise.

So here are some links that may benefit a proper physics person to explain this baffling phenomenon. The pages all seem to disagree with each other as to what causes it.

[1] [2] [3]

[edit] steering geometry

I have looked at the three articles of the three links above. All three of them are in perfect agreement, but the third article discusses the physics in much greater depth.

To expand the wikipedia article, the dynamic behavior of the steering geometry would have to be discussed. The forefork designs of bicycles are little miracles of engineering: if the proportions are just right the steering geometry makes for a forgiving balance behavior of the bike, and it enables smooth steering. By contrast, a bicycle with a vertical steering column would be an absolute nightmare to steer.

Actually, experiment proves otherwise. See The Naïve Bike easily capable of being ridden AndrewDressel 00:01, 19 May 2006 (UTC)

To some motorcyclists it may appear as if their front wheel reads their mind, steering in the direction they want to go. Generally motorcyclists feel that they are thinking themselves through a curve.

A bike is steered by shifting its balance; the front wheel follows these shifts.

Direct experimentation by California Superbike School suggests the opposite. AndrewDressel 03:20, 19 May 2006 (UTC)

The balance is manipulated with well-timed, minute turns of the front wheel. --Cleon Teunissen | Talk 20:31, 10 Mar 2005 (UTC)

[edit] Contradiction

Anyone notice that paragraph two, about gyroscopic effects, appears to be contradicted by the rest of the article?

"Motorcycles turn corners using the gyroscopic roll reaction force of the spinning front wheel."

vs

"If a biker wants to turn to the right, he first throws the bike off balance by a well-timed jolt to the handlebars, 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."

So, is it one, the other, or both? AndrewDressel 03:28, 19 May 2006 (UTC)

Not to mention that precession rate is inversely proportional to spin rate. That means that if "gyroscopic roll reaction" is really the mechanism, it happens twice as slow at 60mph as it does at 30mph. That doesn't sound desirable. Does anyone have a reference to someone who has done the math? AndrewDressel 13:10, 19 May 2006 (UTC)

Since the section about the "gyroscopic roll reaction force" remains unsupported, I've taken it out. I also removed the assertion that countersteering is actually "push steering". Perhaps is it "also known as" or "might better be thought of", but it certainly isn't "actually push steering" any more than it is "actually pull steering". AndrewDressel 12:53, 23 May 2006 (UTC)

[edit] Angle vs Camber Angle

I took out camber angle as it is defined as "the angle made by the wheel". While this is true, it is insignifigant in this context. It is the angle of the entire vehicle that matters: specifically the angle made between a horizontal plane and the plane defined by the two wheel contact points and the combined center of mass of the rider and vehicle. AndrewDressel 14:12, 6 June 2006 (UTC)

[edit] Language

• Tried to make it sound less like a motorcycle riding school lecture.
• Removed mention of "conventional steering" as it contradicts the assertion that "At low speeds countersteering is equally necessary, but the countersteering is so subtle then that it drowns in the continuous corrections that are made in balancing the bike."
• Softened the distinctions between bicycles and motorcycles and focused more on the increased need to consciously countersteer as speed increases.

AndrewDressel 13:30, 14 June 2006 (UTC)

[edit] Walking speed

125.209.173.112 added "above walking pace", but I know of no reason why the physical requirement for countersteering is bounded. Unless someone can find a reference that has shown by physical experiment or some mathematical calculation that countersteering becomes unnecessary, this addition should be reverted. -AndrewDressel 01:37, 23 August 2006 (UTC)

-No reference found, so addition removed. -AndrewDressel 00:37, 25 August 2006 (UTC)

[edit] Better not give two different explanations for one thing

In the current version of the article it is stated:
"Otherwise the bike and rider's inertia or centrifugal force (depending on your frame of reference) will tip the bike over towards the outside of the curve."
I propose to replace that with:
"Otherwise the bike and rider's inertia will tip the bike over towards the outside of the curve."

The remark about dependency on the frame of reference is unhelpful, I think. It suggests there are two different explanations for the tipping over: either inertia or centrifugal force. But the expression 'centrifugal force' is just a very roundabout way of talking about inertia.

If the bike plus rider fails to lean sufficiently inward, then the center of mass of the bike will follow a less sharp curve than the wheels, and consequently the bike will tip over to the outside of the curve. --Cleonis | Talk 05:53, 25 August 2006 (UTC)

After reading the centrifugal force article, I'd lean towards "Otherwise centrifugal force will tip the bike and rider over towards the outside of the curve." From the point of view of the rider, centrifugal force, psuedo or not, is straight forward and easy to understand. I'd leave the wrangling about inertia to other articles. -AndrewDressel 22:35, 25 August 2006 (UTC)

I favor saying things in a straightforward and consistent way. Don't add unnecessary complexity. Take the example of braking: if a front wheel has a lot of stopping power, a motorcycle may flip over when the rider brakes too hard. The cause of flipping over is twofold: the grip of the front wheel, and the inertia of the motorcycle. It would be very weird to claim that the motorcycle, braking too hard with the front wheel, is flipped over by "the forward force". It's the motorcycle's inertia. The straightforward thing to say about steering into a curve without enough lean is that the danger of flippng over is due to the inertia of the motorcycle. --Cleonis | Talk 00:29, 26 August 2006 (UTC)

Well, there we disagree. In the case of braking, in the initial explanation, it is enough to mention the front wheel's stopping force. In the case of turning, I prefer to mention only centrifugal force. It is the two-word phrase commonly used to represent the effect of inertia of an object in circular motion, as explained in the centrifugal force article. It is especially a concept that "those inside the car will often find natural". -AndrewDressel 02:53, 26 August 2006 (UTC)

[edit] Gyroscopic effects

Gyroscopic effects do play a role in bike steering, I think, but it is a rather technical issue, more suitable for a more technical exposition of than for the wikipedia article

In order to get to the required lean, the bike must roll. The front wheel acts like a gyroscope wheel: when there is roll, the wheel's gyroscopic response is to yaw. (For definitions, see pitch, roll, yaw.) I rather suspect that this contributes to the fact that it is possible to steer a bicycle accurately without hands on the handlebars. I also suspect that the gyroscopic effects contribute to the experience of effortlessness of well executed countersteering. --Cleonis | Talk 06:20, 25 August 2006 (UTC)

The gyroscopic effects are discussed in the Bicycle and motorcycle dynamics article. Countersteering is just about the steering input required to initiate a turn. -AndrewDressel 14:54, 25 August 2006 (UTC)

[edit] Very low speed

I have removed the sentence "So at very slow speeds, the bike can be steered while completely upright like a car, involving no countersteering." added by 82.47.85.24

The assertion of "completely upright" is simply wrong because by being in a turn at all, a bike and its rider will experience centrifugul force that must be counteracted by leaning. There are no exceptions.

That the lean angle is very small or that the handlebars are turned far in the direction of the desired turn does not mean that the momentary countersteering necessary to initiate that lean can be skipped. -AndrewDressel 14:52, 3 October 2006 (UTC)

I'm a farily experienced (motor)bike rider, and at very low speed, say walking pace, you do not countersteer (or at least it's optional), even to lean. Dave 04:23, 28 October 2006 (UTC)

How then do you create the necessary lean? -AndrewDressel 03:13, 29 October 2006 (UTC)

At the lowest speeds, you don't lean. Dave 17:01, 29 October 2006 (UTC)

Then how do you counter the Centrifugal force? -AndrewDressel 19:54, 29 October 2006 (UTC)

I don't see why it needs countering - tyre sidewalls should surely take it, as far as I know there's no reason why resultant force on the bike need be vertical (with respect to the bike). Dave

The reason the resultant force (sum of all forces) needs to be vertical with respect to the the bike (exactly coincident with the plane defined by the two wheel contact points and the combined center of mass of the bike and rider) is to keep the bike from falling over. I don't know what you mean by "tyre sidewalls should surely take it." -AndrewDressel 22:01, 29 October 2006 (UTC)

On reflection, as counter intuitive as it seems you must be right, as I can't see any other way there wouldn't be a resultant moment around the centre of mass. Dave 13:34, 30 October 2006 (UTC)

I think what trips us all up is how at lower and lower speeds the necessary but decreasing countersteering becomes overwhelmed by growing adjustments required simply to maintain balance. We are able to unconsciously take advantage of random, minute leans in the desired direction. I guess one could argue, in that case, that conscious countersteering becomes unnecessary. However, in the ideal case of well maintained balance, as I argued with you, there is not a point at which all countersteering become unnecessary. -AndrewDressel 18:21, 31 October 2006 (UTC)