Countersteering confusion : (

Please, forget about this confusing part: "this moves the contact patch Left closer to the center line of the bike".

Pushing forward on the left (or right) hand-grip induces forces that roll the bike over to the left (or right) side.
That happens either you start up from a vertical position or from a right lean.

Furthermore, in order to stop that roll over, precisely at the balance position (vertical or leaned), we briefly countersteer in the opposite direction (like an imperceptible but quick braking burst).

Yeah, I get that. I'm simply interested in the physics of why it occurs. A mental exercise if you will. What specifically brings the bike upright again. I thought it was gyroscopic precession, but that is apparently not the case.

The front wheel is fighting against gravity, and by turning the front wheel we either succumb to gravity (to initiate the turn) or resist gravity (to right the bike after the turn)

The simplest apology is balancing a broom stick on your finger. If you want to move the broom stick the the the right you have to first move your finger to the left to make the broom stick fall toward the right. Once it starts falling to the right you have to move your finger to the right to maintain a constant lean. When you want to stop moving to the right you have to move your finger even faster to the right in order to get back to vertical.

Not exactly.

While we roll over a straight line, the weight vector starts at the CG (combined rider+bike) and points vertically down and aligned with our support points: the contact patches.
We are in vertical balance.

As soon as we deviate from a straight line trajectory, the vector weight tilts from the CG toward the outside of the turn or curvilinear trajectory.
The faster we roll and the smaller is the radius of the circular trajectory, the bigger is the angle of deviation from vertical of that vector.
We people like complicating things, so we decompose that vector into weight and centrifugal force, but in reality that tilted vector is the actual force that the bike feels.
Suddenly, we are out of balance and our contact patches are not aligned with that vector.
We need to roll over the bike in order to re-gain that comfortable balance.
..............but how can we?

oh shit, maths

Ok, Having sobered up some this is getting confusing again....

But throughout the turn our contact patches are out of line with the bike, turning the wheel farther into the turn brings the front wheel contact patch under the bike, bringing the bike upright?

Driving a car. You turn the wheels right, it leans to the left. Same thing with motorcycles.

Put a drink in your cup holder, filled to the brim and investigate.

No Math, no lean, no turn yet.

We are approaching a right hand turn and we know that as soon as we direct the front tire to follow the trace of the right turn (a circular movement), the weight is going to tilt toward the left (due to gyroscopic precession and centrifugal force), putting us out of balance.
Remember: we need to roll over the bike to the right (as we start turning and as the weight vector tilts left) in order to keep that comfortable balance.
..............but how can we?

Then, we use the only thing that we can control with some authority: a turn of the handlebar.
As explained above, if we turn that bar right, we are going to be immediately out of balance, falling on our left side.
If we don't turn the handlebar, we are going to continue going straight and out of the road: no good either.
If we turn the handlebar to the left (pushing the right hand-grip) as the turn begins, we are starting a left turn and making the weight vector tilt toward the right: we are now out of balance and falling, rolling over or leaning the bike to the right (which is exactly what we needed!!!).

Right after the bike is falling to the right and acquiring the right lean angle that we needed to turn right, we can use that rolling inertia that keeps the bike falling to the right in our benefit, not needing that weight vector to be tilted toward the left anymore.

Is only now (some fractions of a second after we steered left) that we can steer to the right, just like we do in a car, making the front tire follow the trace of the curve for as long as it lasts.
By doing that, we are making the weight vector tilt toward the left and getting aligned with both contact patches.
We are in balance again !!! ............not vertically but leaned.
During the turn, we are feeling a little heavier than normal: that is due to the fact that the vector weight gets bigger as it tilts, the more it tilts, the more it grows.
If that curve and speed call for 45 degree lean, the bike and the rider weight 40% more.

We need to revert the direction of the steps in order to abandon the circular movement and lean angle at the end of the curve, resuming linear trajectory.

great analogy. I'll remember it.

I think the last few posts are what hippie and joethe bestestfastesgoodestriderontheplanet are complaining about. interesting but not needed for learning how to steer a motorcycle.

Actually the bike will not right itself. I know we have the perception that it does, but in reality we are making steering input and micro adjustments all the time, the righting of the bike is because of our input.


Did you read this? There is a short segment that explains it much better than I can..
http://www.manicsalamander.com/articles-by-paul/how-to-steer-a-motorcycle-(!).aspx

..

Negative. Gyroscopic forces are a smaller secondary effect. Countersteering would work with no gyroscopic forces at all.

From a full stop, make a u turn and pay attention to what you are doing with the handlebars. If you are countersteering at that point, you are eitgher going the wrong way or are falling.

Which makes my point. Steering a bike, wether it's by direct input at slow speeds or by countersteering at most speeds, is almost instinctual. If you can make a bike change direction, you really don't need to know the physics behind it. You DO need to practice.

Negative. Turning from a full stop you lean the bike with your feet before pulling away. If you were to keep the bike perfectly upright with your feet and pull away with the bars at full left lock, you would fall over to the right.

Right. Practice. And KNOW that pushing right can get you farther over in a right hand turn. Why exactly it happens is an interesting exercise in brain aerobics.

Whenever I make a u turn from a stop, i turn the handlebars in the direction I'm going. Of course I lean the bike, otherwise I wouldn't turn, but that wasn't my point. My point is that countersteering does not work at all speeds.

Most of what we do on a motorcycle, steering wise, is done without thinking. It's the same things we did on a bicycle without knowing what we were doing. That is my point.

Nope. If you're on two wheels and not using your feet, countersteering initiates the turn whether you believe it does or not.

If you lean the bike with your feet before you ride off from stop there's no reason to counter steer. That's because you counter steer to induce a lean and you've already leaned the bike with your feet!

Counter steering works at all speeds above zero.

There is not speed at which you change from direct steer to counter steer. As soon as you move forward and lift your feet you counter steer to balance and turn.

Leaning the bike doesn't turn the bike. Leaning the bike keeps it from falling over toward the outside while turning.

Try it and get back to me.

I do it every day. All the time. Over and over.

Tried it and tried it and tried it again. Always the same, counter steer to balance, counter steer to initiate a turn. If it wasn't that way, then it would be just as easy to balance while stopped as it is while moving 2 mph.

Why is it easier to balance when moving 2mph than when completely stopped? Counter steering.

Counter steering is how we balance, and it's how we initiate a lean.

Not gyroscopes, not shifting your weight, but turning the bars and counter steering.

yes.