[Limit Cornering]

On 12/31/2019 at 11:31 PM, Hotfoot said:

 

Thank you guys both for the great responses.

 

Do you reckon the great guys of bike racing are able to get as close to the "theoretical maximum grip" of their tires mid-corner as their car racing counterparts? Or would the necessity of bringing the bike up at the end cause any conservation? (Apart from psychological response due to danger)

 

Very nice forum this is!

[Limit Cornering]

On 12/31/2019 at 11:31 PM, Hotfoot said:

I do not understand this statement, can you restate it or explain it more?

If I understand your question about how to exit a corner, you are talking about coming out of the corner onto a straight(er) part of track, and you are asking how to change the arc to put the bike in a straighter line, is that right? 

If so, then the answer is yes, you would counter steer to bring up the bike. The momentary instability caused by the countersteering effort is overcome right away by the increased grip afforded by getting the bike more upright (primarily due to your suspension being able to work more effectively). In other words even if the front tire DID slide a little, it would recover, and in fact that is often how riders recover when a tire starts to slide - by standing the bike up. (Sometimes they recover by just staying loose on the bars and the tires regain grip either because they reach better pavement - like a slide on a greasy spot in the road - or because the bike has slowed some.)

Keep in mind, though, that the rider must make a reasonably controlled steering input - a death grip on the bars that restricts bar movement, or a rider pushing on BOTH bars, or an extremely rough bar input could indeed cause a fall.

Edited the OP, you are right regarding what I am asking. 

 

But I do not think you'd be able to bring the bike up at all since the moment you put in extra countersteering (turning the bars in to the corner) the bike would start to fall since it would switch to kinetic friction from rolling friction.

[Limit Cornering]

When you are at the max lean angle and generating as much grip as the tires you have allow in a steady-state, long corner, how do you exit the turn? I think it is theoretically impossible.

You counter-steer into the turn to bring the bike up? That increases the lateral load on tires because you momentarily make the center of mass of the bike+rider system to make a turn, so you fall.

You accelerate? You fall.

You decelerate? You fall, no matter the method. Just shutting down the throttle a bit would increase the lateral force on the tire espically over 45 degrees of lean angle.

Pushing down on the outside peg? The outside peg pushes you up, and since you are leant over, when you go "higher" your center of mass tries to take a tighter turn around the center of the corner. Since "up" is "in" when leaned over. And also the force on the motorcycle by that downward force on the peg increases lateral force on the tires and well, you fall.

Any upper body movement you make that would be of any benefit, could also have been used to take the corner at a higher speed.

 

This really bugs me as a thought.

 

Am I missing something?

 

[Center of gravity]

Does anybody have data for center of gravity heights of motorcycles? No matter the model. There really isn't much info on the net about the subject. Please share them if it is without a rider onboard. 

 

Thank you

[New to the forum]

I am new to the forum and I ride a Ducati 1098 currently. I live in İstanbul/Turkey