Conscious Countersteering

[Smash Allen]

I have had a recent realization that while lean angle is established in part through counter steering, the bike needs the bars to turn to the inside of the corner to make the turn.

“Oh shit I’m going wide, better counter steer more.” That is incorrect. While it will increase lean angle, constant counter steering will prevent the Bike from turning. Just like you can lean a bicycle to one side and continue on a straight path, the same thing is accomplished by staying stiff on the inner arm/bar.

I think :laughing

 

[kurth83]

Robert's question of how to measure countersteering got me thinking (a bad thing possibly).

Pressure on the bars is one thing, yes, but at any given velocity, actual countersteering will cause the bike to change lean angle, so a lean angle measuring device (which I think exist now in cornering ABS units), combined with bar pressure would likely give you everything need.

It might even be possible to forgo the need for bar pressure, yes some pressure may be needed to maintain a lean angle, but actual countersteering can be directly measured by how fast the lean angle changes.

So first derivative of lean angle is countersteering input, can probably be mapped to the exact tire angle if you also record velocity and have some knowledge of the bike's geometry.

Now, would that be useful? Don't know.

 

[rcgldr]

“I’m going wide, better counter steer more.” That is incorrect. While it will increase lean angle, constant counter steering will prevent the bike from turning.

If the rider just steers inwards, the bike will be unbalanced and start to straighten up and/or fall outwards. The lean angle needs to be increased before the bike can be steered inwards more. As mentioned above, on my bike, I have to use some counter-steering torque to hold a lean angle, I use more to increase lean angle, less to decrease lean angle, then go back to only using enough pressure to hold the lean angle, at which point the front tire ends up turned inwards enough for a coordinated turn.

To clarify, I'm referring to counter-steering torque, not direction. If the bike is leaned over mid-turn, then I doubt the front tire is actually turned outwards, it's just turned less inwards so that a turn becomes uncoordinated, increasing lean angle.

 

[Slow Goat]

Robert's question of how to measure countersteering got me thinking (a bad thing possibly).

Pressure on the bars is one thing, yes, but at any given velocity, actual countersteering will cause the bike to change lean angle, so a lean angle measuring device (which I think exist now in cornering ABS units), combined with bar pressure would likely give you everything need.

It might even be possible to forgo the need for bar pressure, yes some pressure may be needed to maintain a lean angle, but actual countersteering can be directly measured by how fast the lean angle changes.

Maybe sensors that track countersteering in degrees with wheel travel/angular measurements (including speed) through a corner?

 

[KnifeySpoony]

“Oh shit I’m going wide, better counter steer more.” That is incorrect.

But that's the best way to get the bike to turn more. Countersteering pressure on the bar does NOT prevent the bar from turning into the corner. You can easily watch your bars turn into a corner while you are countersteering. It may seem strange, but the bar will literally turn the opposite way you are pushing. Try it - get up to speed, take your hands off the bars, coming up to a right hander (or in a big open lot), let go of the bars. While watching the top triple (for easy visual reference), push forward on the right grip with one finger. Keep constant light pressure on it and watch the bars turn to the right, the opposite direction that you are pushing it. You never have to release pressure to allow the tire to turn into the direction of lean. The self correcting force is much stronger than the countersteering force you can apply.

 

[Smash Allen]

But that's the best way to get the bike to turn more. Countersteering pressure on the bar does NOT prevent the bar from turning into the corner. You can easily watch your bars turn into a corner while you are countersteering. It may seem strange, but the bar will literally turn the opposite way you are pushing. Try it - get up to speed, take your hands off the bars, coming up to a right hander (or in a big open lot), let go of the bars. While watching the top triple (for easy visual reference), push forward on the right grip with one finger. Keep constant light pressure on it and watch the bars turn to the right, the opposite direction that you are pushing it. You never have to release pressure to allow the tire to turn into the direction of lean. The self correcting force is much stronger than the countersteering force you can apply.

maybe with the force you use, but i never get light enough to let it turn in. holeshot can attest to that :laughing

 

[sanjuro]

Robert's question of how to measure countersteering got me thinking (a bad thing possibly).

Pressure on the bars is one thing, yes, but at any given velocity, actual countersteering will cause the bike to change lean angle, so a lean angle measuring device (which I think exist now in cornering ABS units), combined with bar pressure would likely give you everything need.

It might even be possible to forgo the need for bar pressure, yes some pressure may be needed to maintain a lean angle, but actual countersteering can be directly measured by how fast the lean angle changes.

So first derivative of lean angle is countersteering input, can probably be mapped to the exact tire angle if you also record velocity and have some knowledge of the bike's geometry.

Now, would that be useful? Don't know.

I think that's the issue for me. From my extensive experience on bicycles, bar input is minimal because I'm steering a 17-25lb vehicle.

But motorcycles do require both body position and handlebar input to initiate tire lean.

 

[KnifeySpoony]

It's too bad we don't have telemetry on bar pressure, steering angle, bike lean angle, etc. Then this argument could be put to rest forever.

 

[stangmx13]

Robert's question of how to measure countersteering got me thinking (a bad thing possibly).

Pressure on the bars is one thing, yes, but at any given velocity, actual countersteering will cause the bike to change lean angle, so a lean angle measuring device (which I think exist now in cornering ABS units), combined with bar pressure would likely give you everything need.

It might even be possible to forgo the need for bar pressure, yes some pressure may be needed to maintain a lean angle, but actual countersteering can be directly measured by how fast the lean angle changes.

So first derivative of lean angle is countersteering input, can probably be mapped to the exact tire angle if you also record velocity and have some knowledge of the bike's geometry.

Now, would that be useful? Don't know.

I doubt its possible to determine bar input from lean angle velocity for 2 reasons. 1. the effectiveness of countersteering is affected by setup - geometry, tires, etc - so ud have some constant in the math. 2. lean angle velocity and resultant lean angle is affected by the riders mass, position, and their motion, and their other inputs such as peg weighting. so, its easy for us to make generalization such as "the lean angle velocity was large, so the counter steer must have been strong as well". but we likely can never know enough specifics to work backwards.

 

[tzrider]

I doubt its possible to determine bar input from lean angle velocity for 2 reasons. 1. the effectiveness of countersteering is affected by setup - geometry, tires, etc - so ud have some constant in the math. 2. lean angle velocity and resultant lean angle is affected by the riders mass, position, and their motion, and their other inputs such as peg weighting. so, its easy for us to make generalization such as "the lean angle velocity was large, so the counter steer must have been strong as well". but we likely can never know enough specifics to work backwards.

Also, speed and turn radius come into play and the turn radius may vary if the rider's line is not consistent. Further, the amount of time it takes to change lean angle is dependent on bar pressure.

What you would want to know is what the force over time looks like at the bars. The only way to really get that accurately is to measure it at the bar.

On the matter of whether one needs to keep pressure on the bars to hold lean angle, it "shouldn't" be necessary. In reality, some conditions must be met for that to be absolutely true. Worn tires sometimes tend to stand up and bike will stand up when the rider is off the gas. With bikes that try to stand up I find that leaning with the bike and locking my outside knee firmly onto the tank reduces the bike's tendency to stand up. By the time I'm rolling on the gas, it's rare to find a bike that won't hold lean angle.

I have encountered a few though. Most often, if the problem isn't tire condition, it's that there is too much trail.

 

[stangmx13]

maybe with the force you use, but i never get light enough to let it turn in. holeshot can attest to that :laughing

no need to exxagerate. u can ride a motorcycle around a race track. the bike turns in and the bars are tracking well-enough. if they weren't, u wouldn't be turning.

if I had to guess at relative magnitudes here, id say that that someone applying too much pressure to inside bar is preventing <10% of maximum steering angle. given that motorcycles have small steering angles at track speeds, <10deg and usually only 5-6deg, u are likely missing out on much less than 1deg of steering angle. its not something u can feel. u can only notice its effects.

concerning the effects - ive experimented with inside bar pressure on long corners. T5-6 at Fontana is a flat medium-size double apex corner where its ez to adjust this stuff. removing or adding inside bar pressure adjusts my line by ~1-2ft from the mid-point of the corner to the 2nd inside apex. in racing, thats a lot. but most trackday-only riders wouldn't even notice.

concerning your first post on this topic - I do think its easier to adjust lean angle during that first counter steer than later when you are already turning. but I don't know why. I can easily pick the bike up anytime during a corner. but I often find it very hard to add noticeable amounts of lean angle mid-corner. it might just be training or lack of skills.

 

[stangmx13]

But motorcycles do require both body position and handlebar input to initiate tire lean.

nope. thats all in your head. you are more comfortable using body position. but it is no way required to initiate a change in lean angle. u might be surprised how fast I can get around a racetrack without moving my head or butt and inch. I do it often for cool down laps after races cuz im tired.

 

[tzrider]

if I had to guess at relative magnitudes here, id say that that someone applying too much pressure to inside bar is preventing <10% of maximum steering angle. given that motorcycles have small steering angles at track speeds, <10deg and usually only 5-6deg, u are likely missing out on much less than 1deg of steering angle. its not something u can feel. u can only notice its effects.

If the steering angle is not exactly correct for the speed and turn radius you're at, the lean angle will change. If a bike is running a little wide when the ride maintains bar pressure and does not run wide when he eliminates bar pressure, it's because with bar pressure, the front was pushing a little bit. When leaned over, the steering is part of the suspension. The tire must be able to wiggle back and forth a little bit to maintain best contact with the road. If the rider interferes with this by leaning on the bars, there will be a small amount of traction loss at the front and the line will widen.

concerning your first post on this topic - I do think its easier to adjust lean angle during that first counter steer than later when you are already turning. but I don't know why. I can easily pick the bike up anytime during a corner. but I often find it very hard to add noticeable amounts of lean angle mid-corner. it might just be training or lack of skills.

This is definitely the case. When you steer the front to the left, the contact patch, which trails behind the steering axis, displaces to the right. When upright, the only resistance you experience to bar input is gyroscopic stability and the trail trying to keep the wheel running straight. When leaned to the right, the rightward displacement of the contact patch is pressing the contact patch "downward" as well as to the right; the deeper deeper the lean angle, the more the movement is "downward." Of course, the road keeps the contact patch from moving downward, so the only thing that can move is the bike chassis, which must be lifted at the steering head. So at high lean angles, an attempt to countersteer more requires the rider to work against the weight of the bike.

 

[Smash Allen]

I often find it very hard to add noticeable amounts of lean angle mid-corner. it might just be training or lack of skills.

[...]at high lean angles, an attempt to countersteer more requires the rider to work against the weight of the bike.

do u even lift



:laughing:thumbup:ride

I’m losing 5 degrees of steering angle at the head and when leaned over st 50+ this is a large effect on location of contact patch. I’m pushing the front every corner

 

[stangmx13]

If the steering angle is not exactly correct for the speed and turn radius you're at, the lean angle will change. If a bike is running a little wide when the ride maintains bar pressure and does not run wide when he eliminates bar pressure, it's because with bar pressure, the front was pushing a little bit. When leaned over, the steering is part of the suspension. The tire must be able to wiggle back and forth a little bit to maintain best contact with the road. If the rider interferes with this by leaning on the bars, there will be a small amount of traction loss at the front and the line will widen.

yes, theoretically, the steering angle must be perfectly correct otherwise the lean angle will change. but in practice, everything is flexible. I suspect there is a small range of steering angles that allow a motorcycle to be stable enough to consider it to have a constant lean angle. of course its not constant because of oscillations introduced by all the disturbances and inputs, but its close enough.

I think the flip side is true too... theres is a small range of lean angles that accomplishes X turning radius at Y speed. this goes hand in hand with bar pressure and peg weighting an all those small extra inputs one can make. we get a little bit of tire/chassis/suspension flex or movement and all the values change just a tiny bit, but the overall result is mostly unchanged.

This is definitely the case. When you steer the front to the left, the contact patch, which trails behind the steering axis, displaces to the right. When upright, the only resistance you experience to bar input is gyroscopic stability and the trail trying to keep the wheel running straight. When leaned to the right, the rightward displacement of the contact patch is pressing the contact patch "downward" as well as to the right; the deeper deeper the lean angle, the more the movement is "downward." Of course, the road keeps the contact patch from moving downward, so the only thing that can move is the bike chassis, which must be lifted at the steering head. So at high lean angles, an attempt to countersteer more requires the rider to work against the weight of the bike.

thats an interesting effect. I really wonder what the relative magnitudes are, of say bar pressure required at lean vs straight up. the motorcycle accomplished a lot while fighting its mass, so I wouldn't think itd be THAT much harder to turn the bars with lean. and its not like all the mass is on the steering head. and the bike will also rotate about its CG a tiny bit instead of lifting. hmmm

 

[stangmx13]

I’m losing 5 degrees of steering angle at the head and when leaned over st 50+ this is a large effect on location of contact patch. I’m pushing the front every corner

wut? no, u aren't losing 5deg of steering angle. ud end up with negative steering angle for a lot of corners and would fall over. this is just more exaggeration.

no one is strong enough to stop or prevent the bikes positive steering force like KnifeySponny said. u can resist it dynamically, while its happening, so that u end up with more lean angle that intended. and u can fight it after your lean angle is set so that u run wide. but u aren't going to stop the tire from pointing inwards with a 100% magnitude change.

 

[Smash Allen]

wut? no, u aren't losing 5deg of steering angle. ud end up with negative steering angle for a lot of corners and would fall over. this is just more exaggeration.

no one is strong enough to stop or prevent the bikes positive steering force like KnifeySponny said. u can resist it dynamically, while its happening, so that u end up with more lean angle that intended. and u can fight it after your lean angle is set so that u run wide. but u aren't going to stop the tire from pointing inwards with a 100% magnitude change.

k, exaggerating makes it easier to convey the idea that im stiff on inside arm and it pushes me wide

 

[tzrider]

k, exaggerating makes it easier to convey the idea that im stiff on inside arm and it pushes me wide

How wide are you? Do you have an example of a turn at one of the local tracks and about how much you're missing the apex by?

 

[Smash Allen]

How wide are you? Do you have an example of a turn at one of the local tracks and about how much you're missing the apex by?

Turn 1 Thunderhill east, 6 feet? Though I’m probably exaggerating

 

[Smash Allen]

here's a screen grab from friday practice round 5