Another fun quiz on cornering :-)

[Tufbusa]

Ken, go visit this thread : https://www.hayabusa.org/forum/general-bike-related-topics/179588-effective-lean-angle.html and you will find the answer to this quiz. Then, I think you will agree that Professor Roll Angle's theory has little if anything to do with this topic.

 

[mynewride]

As long as the speed and radius remains constant then the effective lean angle will not change; however the visual angle will be reduced by the change in COG. Am I on track?

 

[Tufbusa]

As long as the speed and radius remains constant then the effective lean angle will not change;

:exclamation: Attention Kmart shoppers, we have a "WINNER"! Congratulations!

That is exactly correct. Radius & Speed determines Effective Lean Angle! One or the other must be increased or decreased in order for the effective lean angle to be changed. Visual lean angle only affects the position of the bike in reference to the horizontal plane. As we all know, moving the bike and rider CG to the inside decreases the visual lean resulting in getting up on the fatter part of the tire where the traction is increased and allows us to increase speed thus increasing EFFECTIVE lean angle.

As shown below, lowering the center of gravity actually decreases the bike's visual lean angle thus decreasing the available traction.

These factors are all tied together. You cannot change one without changing the other. The more we know and understand about cornering the better we will become at conquering corners.

You must understand cornering before you can conquer corners. Keith Code

 

[mynewride]

As shown below, lowering the center of gravity actually decreases the bike's visual lean angle thus decreasing the available traction.

so at less visual angle there is less available traction? I thought that the more upright the bike "visual angle" was the more available traction there was.

example: 30mph corner all things held constant (ie line, speed, and radius). If I go through the corner tucked first and sitting up second, my visual angle of the bike will be less when tucked and available traction will be less when tucked? The effective angle will remain constant.

 

[Tufbusa]

so at less visual angle there is less available traction?

No! Less visual lean angle means standing the bike up more on the fat part of the tire which gives "MORE" traction.

I thought that the more upright the bike "visual angle" was the more available traction there was.

example: 30mph corner all things held constant (ie line, speed, and radius). If I go through the corner tucked first and sitting up second, my visual angle of the bike will be less when tucked and available traction will be less when tucked?

If you begin the corner sitting up then tuck it will move the CG of bike & rider but will not change the effective lean angle unless you change radius or speed.

The effective angle will remain constant.

Good Post!

 

[ogre]

purple, because bumble bees can't swim in tapioca.

 

[GSXcite]

Well here's a plate of whole wheat buttermilk pancakes with fresh blackberries finished with a maple syrup bourbon carmilized apple compote.



cheers
ken

If I ate that plate of pancakes, it would increase MY roll angle!

 

[Deviousbusa]

I'll answer this from a racer perspective. The question sounds simple however, there are a lot of variables to consider. First, the corner itself, is it an increasing radius? decreasing, constant radius corner? What is the camber like? Flat...positive/negative? Is the surface bumpy? Smooth? Dry or wet...the list goes on and on...

Next, comes the entry speed...going in slow to point and shoot the corner? Are you trailing in all the way to the apex? Are you a newer rider and early apexing? Once all that is determined, from what I have seen at the track many many times is that if you sit in the middle of your seat, you do not have as much weight on the inside of the turn to tilt the bike in so, you have to lean the bike more which will give you a more extreme angle VS hanging off the bike which allows you to keep the bike more upright and allow the rider to drag knee (or these days elbow/shoulder) and keep the bike more upright and allow the tire to have a larger contact patch.

Which way is right? Well, any racer will tell you that there is no "ideal" body position or line. I know racers who do not hang off much yet, run the same times as riders who do hang off the bike. In the end, it boils down to doing what works for you to get through the turns fast. Now, keeping everything in mind I will leave you with this...the faster you can pick the bike up out of the turn, the faster you are going to be able to get on the throttle. So, ideally...that is what you want in terms of the balance of braking/line choice/and body position. Anytime you are coasting or braking you are NOT going faster so...any racer will tell you that the goal is to minimize the braking/coasting on a race track.

I hope this helps! I'm by no means an "expert" so, this is simply some of what I've learned in my years of racing. I would also recommend keeping the "fast" riding on the track as street is not as forgiving.

 

[albatross]

Yes, I don't believe it will change the lean angle whether you stand on the seat or tuck behind the screen. This is the LEAN ANGLE we are talking about remember, not the speed you can take the corner at nor the stability. It would be more sensible to tuck lower in a corner for obvious reasons but I don't believe that has anything to do with the lean angle. When the footrest hits the ground that's a little too much lean angle whether riding sitting on the seat back to front, standing on the seat or sitting normally surely...?!

 

[lokey997]

impressive discussion. Gotta say this simple question does get the mind going on something we take for granted everyday. Camping here for more!!!

 

[Tufbusa]

I'll answer this from a racer perspective. The question sounds simple however, there are a lot of variables to consider. First, the corner itself, is it an increasing radius? decreasing, constant radius corner? What is the camber like? Flat...positive/negative? Is the surface bumpy? Smooth? Dry or wet...the list goes on and on...

Next, comes the entry speed...going in slow to point and shoot the corner? Are you trailing in all the way to the apex? Are you a newer rider and early apexing? Once all that is determined, from what I have seen at the track many many times is that if you sit in the middle of your seat, you do not have as much weight on the inside of the turn to tilt the bike in so, you have to lean the bike more which will give you a more extreme angle VS hanging off the bike which allows you to keep the bike more upright and allow the rider to drag knee (or these days elbow/shoulder) and keep the bike more upright and allow the tire to have a larger contact patch.

Which way is right? Well, any racer will tell you that there is no "ideal" body position or line. I know racers who do not hang off much yet, run the same times as riders who do hang off the bike. In the end, it boils down to doing what works for you to get through the turns fast. Now, keeping everything in mind I will leave you with this...the faster you can pick the bike up out of the turn, the faster you are going to be able to get on the throttle. So, ideally...that is what you want in terms of the balance of braking/line choice/and body position. Anytime you are coasting or braking you are NOT going faster so...any racer will tell you that the goal is to minimize the braking/coasting on a race track.

I hope this helps! I'm by no means an "expert" so, this is simply some of what I've learned in my years of racing. I would also recommend keeping the "fast" riding on the track as street is not as forgiving.

I think you may have missed the point here? This thread is not about entry speeds, camber, surface condition nor smooth control of the bike. This thread is about distinguishing the difference between visual lean angle and Effective lean angle. Ask this question to a hundred racers and I'd guess maybe ten has ever heard of Effective lean angle.

 

[Tufbusa]

Yes, I don't believe it will change the lean angle whether you stand on the seat or tuck behind the screen. This is the LEAN ANGLE we are talking about remember, not the speed you can take the corner at nor the stability. It would be more sensible to tuck lower in a corner for obvious reasons but I don't believe that has anything to do with the lean angle. When the footrest hits the ground that's a little too much lean angle whether riding sitting on the seat back to front, standing on the seat or sitting normally surely...?!

You are on the right track. Remember that no matter what the rider does by using his body as ballast will change the Effective lean angle. It will only affect the visual lean angle unless the speed or radius is changed. Only speed and radius can affect the "Effective" lean angle. There are three parts to the equation of cornering on two wheels "Speed - Radius - Effective Lean Angle). Changing any one of them will also change at least one of the others. You cannot change one without changing one or both of the others.

 

[Deviousbusa]

I think you may have missed the point here? This thread is not about entry speeds, camber, surface condition nor smooth control of the bike. This thread is about distinguishing the difference between visual lean angle and Effective lean angle. Ask this question to a hundred racers and I'd guess maybe ten has ever heard of Effective lean angle.

...sorry...then I have no idea what you're after! Sorry I couldn't help!

 

[Blrry]

"Radius & Speed determines Effective Lean Angle! One or the other must be increased or decreased in order for the effective lean angle to be changed. Visual lean angle only affects the position of the bike in reference to the horizontal plane. As we all know, moving the bike and rider CG to the inside decreases the visual lean resulting in getting up on the fatter part of the tire where the traction is increased and allows us to increase speed thus increasing EFFECTIVE lean angle. "

How does this make sense when you compare it to the text in your attached image? It states:

"With a low Center of Gravity, due to the width of the tire and the area actually touching the groud, your effective lean angle is actually 30 degrees. In other words, you (sic) bike is turning as if it were leaning only 30 degrees."

and

"When you raise your C.G. you are decreasing the effect of the width of the tire inside contact patch. Your effective lean angle is 40 degrees."

The graphic says nothing about changing the radius or the speed, and instead states that lowering the C.G. changes the EFFECTIVE lean angle to 30 degrees, and raising the C.G. changes the EFFECTIVE lean angle to 40 degrees. So either your explaination is wrong, or your graphic is wrong (as near as I can tell) and I still don't know what the heck you're trying to explain...

Maybe one in 10 racers can't explain it, because whoever was teaching them couldn't clearly explain it either! I know I'm confused!

 

[Lamb busa]

what a fun quiz! everybody really got there fun on!!!