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-   -   Counter Steering - When to Use? (https://www.bikeforums.net/road-cycling/1034744-counter-steering-when-use.html)

 Abe_Froman 05-01-17 09:12 AM

This has gone on too long with far too much conjecture. This isn't something that is really up for debate...while bicycle physics are relatively complex and fairly interesting...this is still like middle school physics class stuff. It's been covered before and solved.

https://en.wikipedia.org/wiki/Bicycl...cycle_dynamics

Countersteering
Main article: Countersteering
In order to initiate a turn and the necessary lean in the direction of that turn, a bike must momentarily steer in the opposite direction. This is often referred to as countersteering. With the front wheel now at a finite angle to the direction of motion, a lateral force is developed at the contact patch of the tire. This force creates a torque around the longitudinal (roll) axis of the bike, and this torque causes the bike to lean away from the initially steered direction and toward the direction of the desired turn. Where there is no external influence, such as an opportune side wind to create the force necessary to lean the bike, countersteering is necessary to initiate a rapid turn.[48]

While the initial steer torque and steer angle are both opposite the desired turn direction, this may not be the case to maintain a steady-state turn. The sustained steer angle is usually in the same direction as the turn, but may remain opposite to the direction of the turn, especially at high speeds.[52] The sustained steer torque required to maintain that steer angle is usually opposite the turn direction.[53] The actual magnitude and orientation of both the sustained steer angle and sustained steer torque of a particular bike in a particular turn depend on forward speed, bike geometry, tire properties, and combined bike and rider mass distribution.[23] Once in a turn, the radius can only be changed with an appropriate change in lean angle, and this can be accomplished by additional countersteering out of the turn to increase lean and decrease radius, then into the turn to decrease lean and increase radius. To exit the turn, the bike must again countersteer, momentarily steering more into the turn in order to decrease the radius, thus increasing inertial forces, and thereby decreasing the angle of lean.[54]

No hands
While countersteering is usually initiated by applying torque directly to the handlebars, on lighter vehicles such as bicycles, it can also be accomplished by shifting the rider’s weight. If the rider leans to the right relative to the bike, the bike leans to the left to conserve angular momentum, and the combined center of mass remains nearly in the same vertical plane. This leftward lean of the bike, called counter lean by some authors,[45] will cause it to steer to the left and initiate a right-hand turn as if the rider had countersteered to the left by applying a torque directly to the handlebars.[48] This technique may be complicated by additional factors such as headset friction and stiff control cables.

The combined center of mass does move slightly to the left when the rider leans to the right relative to the bike, and the bike leans to the left in response. The action, in space, would have the tires move right, but this is prevented by friction between the tires and the ground, and thus pushes the combined center of mass left. This is a small effect, however, as evidenced by the difficulty most people have in balancing a bike by this method alone.

 joejack951 05-01-17 09:14 AM

Originally Posted by wphamilton (Post 19550722)
Turning opposite the lean (or equivalently opposite to the direction of turn) is the definition of counter-steering.

In [four-wheeled] motorsports, counter-steering is turning the wheels in the opposite direction of the direction you really want to go, i.e. turning the wheels to the right when you are trying to turn left, for the purpose of controlling a slide. On that basis, 'counter-steering' has little to no relevance to cycling. To go left, you must first turn right then turn left. And turning the bars left actually acts as a way to keep you from turning too hard left/stopping a left turn.

Boiled down, you don't really steer a bike. You just keep it from falling over :D

 Stucky 05-01-17 09:14 AM

Originally Posted by grolby (Post 19550703)
What are we arguing here? I think we're on the same page. I know what my tire tracks will look like if I make a sharp turn. I'm saying that because balancing and turning a bike is fully internalized, I don't really buy that people will try to turn the handlebars toward the direction they want to go and go the wrong way as a result.

THAT, essentially, is the essence of first learning to ride a bike. When we are, say, 6 years old, or what ever age we are when we first hop on a 2-wheeler, not having any previous experience, our instinct is to steer in the direction we want to go- even after learning how to balance and stay upright in a straight line.

Everything after learning to go straight, is just a matter of learning to overcome the initial instinct which makes us want to do the opposite of what turning the bike requires.

 Abe_Froman 05-01-17 09:16 AM

Originally Posted by grolby (Post 19550703)
What are we arguing here? I think we're on the same page. I know what my tire tracks will look like if I make a sharp turn. I'm saying that because balancing and turning a bike is fully internalized, I don't really buy that people will try to turn the handlebars toward the direction they want to go and go the wrong way as a result.

That's not true. Bikes are self balancing.

 joejack951 05-01-17 09:19 AM

Originally Posted by grolby (Post 19550641)
I suppose it's just my own experience, but I find it so very hard to believe these stories. I've never, ever in my life turned my bike in the opposite direction from what I intended. Not even in an emergency or when I was startled. I could no more do that than turn in the opposite direction I intended while running. Maybe I just have a high degree of fluency in handling a bike, or maybe people lose balance when doing the right thing in a scary situation (you can certainly still crash if you're just too abrupt with your input) and it gets attributed to not having knowledge of counter-steering because everyone is so hung up on how "counterintuitive" it is (it's the literal opposite of counterintuitive, but never mind). If I want to turn my bike gently to the left, I turn gently to the left. If I want to turn my bike hard to the right, I turn hard to the right. I don't have to think about what I'm doing with the handlebar. I just do what I need to do to achieve the result I want.

It sounds like you do, based on my own observed deficiencies and from what I've heard from others. I'm curious how much you rely on your rear brake to stop quickly in good traction situations.

 FBinNY 05-01-17 09:22 AM

Originally Posted by grolby (Post 19550703)
What are we arguing here? I think we're on the same page. I know what my tire tracks will look like if I make a sharp turn. I'm saying that because balancing and turning a bike is fully internalized, I don't really buy that people will try to turn the handlebars toward the direction they want to go and go the wrong way as a result.

I'm sorry, I sometimes don't know my right from left. When you said you never had a problem turning in the direction you meant, I read that as right for right, now I see, that yes, you meant left for right and vice versa.

However, failure to counter-steer when panicked is all too common among news, especially those who are generally 4 wheel drivers, for whom, two wheels are something different. This is partly why Moto renters in resort areas have such a high accident rate. The necessary motion controls aren't programmed and they steer with their hands the same way they do in a car.

You see a related phenomenon when non boaters first try to use an outboard motor boat. In a panic, they'll bring the tiller to the right to turn right. What's interesting is that they manage general maneuvers fine, and only screw it up when making a full rudder panic turn.

 grolby 05-01-17 09:28 AM

Originally Posted by wphamilton (Post 19550722)
The continual input to stay upright does not require countersteering - that's the difference! You only need to turn the bike into the lean. Too much, and you're falling the other way, you again turn into that lean. You never have to turn opposite the change in lean for stability (although you do need to turn the bar in the direction you want to go, obviously). Turning opposite the lean (or equivalently opposite to the direction of turn) is the definition of counter-steering. The difference is in the direction of the control.

It's the same as tightening or loosening a bolt. The dynamics are the same, the mechanical principles are the same, but in different directions they are two different actions undertaken with two different results.

At this point, I can only throw my hands in the air. You say these actions are as distinct as turning a bolt in different directions. I say they aren't. Every correction becomes an overcorrection, that's what dynamic balance implies. It's all the same thing.

I'll put it this way: if you're leaned over in a turn and want to straighten up your line and go a little wider, you turn the handlebars into the lean. Or you may be exiting the turn and straightening up, or changing to a turn in the opposite direction. According to the definition you give above, because this is turning into the lean, it's not counter-steering. But it is! Just because you're leaned over doesn't mean you aren't balancing. You are, all the time. Straightening up from a lean is an act of dynamic unbalancing in exactly the same way that initiating a lean is. They aren't any different. That's why this distinction you're making doesn't make sense. Anything you do on a bike is a constant back and forth of unbalancing and rebalancing. If you insist that counter-steering is unbalancing and steering is rebalancing, then a bike rider is switching between the two multiple times a second as they ride along. You can have it your way if you want, but that doesn't strike me as a useful way to describe what's happening as a cyclist balances a bike.

 grolby 05-01-17 09:37 AM

Originally Posted by Abe_Froman (Post 19550761)
That's not true. Bikes are self balancing.

A typical bicycle is self-balancing if you give it a good push without a rider, but that has very little to do with how a rider balances on a bicycle. The mass of the rider so much exceeds that of the bike that the bike can't exert enough force through it's self-balancing mechanism to stay up on its own. It would be easier to learn to ride a bike if they did all the work. This could be a key difference between bicycles and motorcycles. As I said, I have no experience with motorcycles, but the much greater mass could make them more self-balancing than a bicycle. But I don't know.

Originally Posted by joejack951 (Post 19550772)
It sounds like you do, based on my own observed deficiencies and from what I've heard from others. I'm curious how much you rely on your rear brake to stop quickly in good traction situations.

Heh, the old brake discussion. I generally use both brakes at once, but I don't rely on the rear very much.

 joejack951 05-01-17 09:45 AM

Originally Posted by grolby (Post 19550825)
Heh, the old brake discussion. I generally use both brakes at once, but I don't rely on the rear very much.

I asked because it is amazing how many experienced cyclists consider the front brake 'dangerous.' I have even been called out a few times as being stupid/clueless a few times for building a bike with a front disc brake and rear caliper. Much like knowing how to steer properly, understanding your brakes by practicing can go a long way in an emergency situation.

 wphamilton 05-01-17 12:26 PM

Originally Posted by grolby (Post 19550798)
At this point, I can only throw my hands in the air. You say these actions are as distinct as turning a bolt in different directions. I say they aren't. Every correction becomes an overcorrection, that's what dynamic balance implies. It's all the same thing.

I'll put it this way: if you're leaned over in a turn and want to straighten up your line and go a little wider, you turn the handlebars into the lean. Or you may be exiting the turn and straightening up, or changing to a turn in the opposite direction. According to the definition you give above, because this is turning into the lean, it's not counter-steering. But it is! Just because you're leaned over doesn't mean you aren't balancing. You are, all the time. Straightening up from a lean is an act of dynamic unbalancing in exactly the same way that initiating a lean is. They aren't any different. That's why this distinction you're making doesn't make sense. Anything you do on a bike is a constant back and forth of unbalancing and rebalancing. If you insist that counter-steering is unbalancing and steering is rebalancing, then a bike rider is switching between the two multiple times a second as they ride along. You can have it your way if you want, but that doesn't strike me as a useful way to describe what's happening as a cyclist balances a bike.

Throwing your hands up is likely the wrong approach to understand a concept that you disagree with.

If you wanted to be more rigorous in terms of something like classical mechanics, you could think of balance as vector distance from the center of mass extended to the line of the wheels' contact points, and the composite vector comprised of gravity and centripetal acceleration. You can determine torque and other force measures from that foundation. You could then derive a function of the change in balance dependent on the change in turn angle of your handlebars. If you did this - just conceptually if you like, no reason to go through calculations - you will find that the sign of the counter-steering input is the negative of the sign of balancing steering inputs. In every case where the bike is on the ground rolling, without exception. This is the analytical basis for distinguishing the two.

 rbrsddn 05-01-17 12:36 PM

If you ride two wheels, you countersteer without having to know how. you just do. Now, knowing how to countersteer in a life or death situation, where you have to swerve Now, That's where knowing what it is and practicing can save your life. Plus, you are a much smoother rider when you know how to apply pressure on the bars.

 Bandera 05-01-17 12:37 PM

"Every single-track vehicle steers in the same way. This includes bicycles, motorcycles, unicycles:
Press right; go right., Press left; go left."

Countersteering Motorcycles

 grolby 05-01-17 01:10 PM

Originally Posted by wphamilton (Post 19551392)
Throwing your hands up is likely the wrong approach to understand a concept that you disagree with.

If you wanted to be more rigorous in terms of something like classical mechanics, you could think of balance as vector distance from the center of mass extended to the line of the wheels' contact points, and the composite vector comprised of gravity and centripetal acceleration. You can determine torque and other force measures from that foundation. You could then derive a function of the change in balance dependent on the change in turn angle of your handlebars. If you did this - just conceptually if you like, no reason to go through calculations - you will find that the sign of the counter-steering input is the negative of the sign of balancing steering inputs. In every case where the bike is on the ground rolling, without exception. This is the analytical basis for distinguishing the two.

The issue isn't that I don't understand that. The issue is that the sign will flip merely by maintaining the same steering input. "Balancing" vs "unbalancing" inputs are differentiated only by time. A balancing steering input always ultimately becomes an unbalancing steering input, which requires a new balancing steering input, which becomes an unbalancing input. And the definition of counter-steering used by most people encompasses both anyway. That you can define a movement, at a single point in time, as increasing the distance between the wheels and the balance point or decreasing it, is obvious. I don't dispute it. What I dispute is that this distinction conforms in a meaningful way to the concept of "counter-steering" and whether that concept has utility as distinguished from steering in general.

Let me present a simple model of how steering works to get across why I think the distinction you make is irrelevant. Just forget about where the balance point is, it doesn't actually matter. We can completely abstract it away, in fact. Turning the handlebars induces a change in the angular acceleration of the bicycle, pivoting around the wheel contact points. Turning the bars to the right will decrease the clockwise acceleration. Turning the bars left will increase the clockwise acceleration. When the bike is balanced against all forces, the acceleration is zero. This can happen at any possible lean angle. When the bike is slowing a clockwise rotation or rotating counterclockwise, the clockwise acceleration is negative.

The ultimate, ultra-simplified point here is that turning the bars to the right causes the bicycle to revolve counterclockwise around the contact points and turning the bars left causes the bike to revolve clockwise around the contact points. And that's a) essentially the point counter-steering proponents are making, and b) the only way that exists to steer a bicycle. Here we are getting into the weeds of whether you're moving the balance point closer or further away, and that's fine if you want to draw some force diagrams at Time A and Time B and say "see, the sign of the steering input defines what is steering and what is counter-steering." But I think that's missing the whole point of the counter-steering concept, which is: you turn the bars right to go left, and left to go right. And my point is: turns out, that's just how steering a bike always works. 100% of the time. The mathematical distinction you want to make is fine, but it's not what people are talking about and I don't think it's functionally relevant either.

 goenrdoug 05-01-17 02:38 PM

maybe it would be best if we all just rode one of these

 wphamilton 05-01-17 03:16 PM

Originally Posted by grolby (Post 19551520)
...
Let me present a simple model of how steering works to get across why I think the distinction you make is irrelevant. Just forget about where the balance point is, it doesn't actually matter. We can completely abstract it away, in fact. Turning the handlebars induces a change in the angular acceleration of the bicycle, pivoting around the wheel contact points. Turning the bars to the right will decrease the clockwise acceleration. Turning the bars left will increase the clockwise acceleration. When the bike is balanced against all forces, the acceleration is zero. ..

Lean angle, turn radius and angular velocity are dependent when the forces are in balance. Given any two, calculate the third. Counter-steering does not have those forces in balance however. By moving the bike to one side under the center of mass, it produces an inbalance and you are falling over until you turn again into your intended turn. So I don't think that your model is sufficient.

 Chandne 05-01-17 03:21 PM

We use it very often and very gently on turns (esp faster ones) but I have to (rarely but it happens) employ it on a new and suddenly decreasing-radius turn or if I have entered a bit too hot. We use it more agressively while riding motorcycles since speeds are higher. If you ever do track days, you will learn this really fast.

 JFraz 05-01-17 04:25 PM

Originally Posted by f4rrest (Post 18245570)
The counter steer is subtle and starts the lean. You just don't notice it.

Steering a 1 liter sportbike into a sweeping turn requires more counter steer than it does on a lightweight, twitchy road bike.

I recall having to put pressure on the inner bar. Not so much on a bicycle.

Agreed. Also, adding trail brake to the equation when on a sport bike.

Ive thought about attempting it on a road bike. Not quite sure I have the balls, lol.

 JFraz 05-01-17 04:26 PM

Originally Posted by Chandne (Post 19551931)
We use it very often and very gently on turns (esp faster ones) but I have to (rarely but it happens) employ it on a new and suddenly decreasing-radius turn or if I have entered a bit too hot. We use it more agressively while riding motorcycles since speeds are higher. If you ever do track days, you will learn this really fast.

Yup. And some trail brake, as mentioned in my above post.

Ride safe.

 Chandne 05-01-17 04:35 PM

Braking on 1.5 mm of rubber (when leaned slightly over) has not-so-great results, I have learned. :)

 Bike Gremlin 05-13-17 09:32 AM

Related to counter steering, wrote an article on fast (downhill, on paved roads) cornering on a bicycle. Tried to explain all the important aspects as briefly as possible (without missing anything important). All the suggestions and corrections are more than welcome:

Fast cornering on a bicycle - on paved roads - Cycle Gremlin

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