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Discussion Starter #61
Pro riders have the very same problem. If you watch different youtube channels, you will see/hear all the legendary myths.
For example WSBK world champion/ campions will repeat some of the same myths that are heard in any track day paddocks.
Amen to that.
 

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Discussion Starter #62
I have a bit of a problem with the way a few of the threads I've seen have been going. After a little back-and-forth the tone gets quite adversarial and honestly I don't think that's why people come to these forums. This is a community where people go to share ideas & experiences, get information and chat with like-minded people. Let's keep that in mind shall we?
 

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There are already a lot of data available in internet, just use google/ try different search words, you might need do pay a few dollars to get some of the documents.
But anyway the truth is already out there. :)

And if you want a theoretical approach, just read; Vittore Cossalter - Motorcycle Dynamics, and you will be able to answer to your own questions.
but googling something is so much work. it's not easy like when i was a kid and had to go to a library, open an encyclopedia, and paraphrase things:LOL:
 

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I often hear people mentioning that certain techniques make a motorcycle "easier to turn". However I have heard a reputable source say in the same talk that the brakes make the bike easier to go in the turn, and then that the throttle makes the bike "easier to turn" coming off the corner. And what does "easier to turn" actually mean? The bars become lighter? The bike is more responsive with the same pressure? Would the brakes make the bars lighter or heavier? Thoughts?
I have a bit of a problem with the way a few of the threads I've seen have been going. After a little back-and-forth the tone gets quite adversarial and honestly I don't think that's why people come to these forums. This is a community where people go to share ideas & experiences, get information and chat with like-minded people. Let's keep that in mind shall we?
I think this is a great discussion and everyone holds a valid point! I’ve learned a lot and value in everyones opinion so far! I agree with 80-100% braking should be at upright or close to 5% lean as it’s most efficient then, however you can brake at 10-15% Lean with 80% Braking but it’s Not as efficient and wants to naturally go wide but that’s easily compensated with additional lean and trailing off with throttle control, so many methods work but body weight, position and balls really come into play, too slow of an entry speed to me is a nightmare, can’t hold the line well and I’m all over the place, once I gradually increased my entry speed everything fell into place better and I could exercise different techniques. someone mentioned rpms revs come into play and I do agree with the gyroscope effect even if its ever so slight but especially at higher rpms which you should be in anyway for better throttle control and response. So seeing reply’s with “incorrect“ is about the best way to disagree but add value with your Opinion. We ride Sportbikes and one wrong move at lean in a corner will hurt or put us in ER or worse, so being passionate about our different techniques is great. I want to hear what works for someone else even if I disagree. Polite and cordial isn’t the objective here since where all so passionate about riding and understand the risks versus thrills. We are not “Yes“ men or woman so disagreeing and back and forth is the first step to more knowledge. Just my 2 cents worth! Oh to give my opinion to the original question “what makes steering input/turning easier” the slower you go with less forces applied to the tire makes it steer easy In corners ? Yes but that very boring. that’s should be a question for the cruiser forum!:sneaky:
 

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I think this is a great discussion and everyone holds a valid point! I’ve learned a lot and value in everyones opinion so far! I agree with 80-100% braking should be at upright or close to 5% lean as it’s most efficient then, however you can brake at 10-15% Lean with 80% Braking but it’s Not as efficient and wants to naturally go wide but that’s easily compensated with additional lean and trailing off with throttle control, so many methods work but body weight, position and balls really come into play, too slow of an entry speed to me is a nightmare, can’t hold the line well and I’m all over the place, once I gradually increased my entry speed everything fell into place better and I could exercise different techniques. someone mentioned rpms revs come into play and I do agree with the gyroscope effect even if its ever so slight but especially at higher rpms which you should be in anyway for better throttle control and response. So seeing reply’s with “incorrect“ is about the best way to disagree but add value with your Opinion. We ride Sportbikes and one wrong move at lean in a corner will hurt or put us in ER or worse, so being passionate about our different techniques is great. I want to hear what works for someone else even if I disagree. Polite and cordial isn’t the objective here since where all so passionate about riding and understand the risks versus thrills. We are not “Yes“ men or woman so disagreeing and back and forth is the first step to more knowledge. Just my 2 cents worth! Oh to give my opinion to the original question “what makes steering input/turning easier” the slower you go with less forces applied to the tire makes it steer easy In corners ? Yes but that very boring. that’s should be a question for the cruiser forum!:sneaky:
you can brake with 100% at 10-15% lean easily. speedfin is again relaying folklore that is easily debunked with few youtube videos.
 

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I agree it can be done! I’ve done it! Your both right on this one! However it feels like I’m on the edge with stress/forces to my front tire all at the same time ( hard braking with lean) I prefer to be hard braking (90-100%) with as little lean as possible until I start trailing off and dropping in while adding lean with aggressive throttle control.
I think thats what speedfin Is saying?! for me it’s how do I get around the corner the fastest possible with the lowest amount of risk Level. This formula has seemed to work for me over the years.
 

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you can brake with 100% at 10-15% lean easily. speedfin is again relaying folklore that is easily debunked with few youtube videos.
If you are really bad with brakes, you can brake easily 100% even if you are leaning 50-75%, or 10-15%, or 15-50%.
 

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I agree it can be done! I’ve done it! Your both right on this one! However it feels like I’m on the edge with stress/forces to my front tire all at the same time ( hard braking with lean) I prefer to be hard braking (90-100%) with as little lean as possible until I start trailing off and dropping in while adding lean with aggressive throttle control.
I think thats what speedfin Is saying?! for me it’s how do I get around the corner the fastest possible with the lowest amount of risk Level. This formula has seemed to work for me over the years.
If you are good with brakes, and you can use 100% of the front tyre traction to braking, then you cannot lean the bike while braking 100%.

If you are bad with brakes, then you do not use 100% of the front tyre traction to braking, and you can lean the bike while braking "100%".
The worse you are with the brakes, the more you can lean, while braking "100%".
 

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Discussion Starter #70
If you are good with brakes, and you can use 100% of the front tyre traction to braking, then you cannot lean the bike while braking 100%.

If you are bad with brakes, then you do not use 100% of the front tyre traction to braking, and you can lean the bike while braking "100%".
The worse you are with the brakes, the more you can lean, while braking "100%".
In your opinion is there a torque on the bars from trailing the brakes? If so, would that make it easier to steer, harder, or no difference? Also, would this change significantly with lean, for example 30 degrees versus 10 degrees.
 

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In your opinion is there a torque on the bars from trailing the brakes? If so, would that make it easier to steer, harder, or no difference? Also, would this change significantly with lean, for example 30 degrees versus 10 degrees.
213790



Motorcycle Steering Torque Decomposition
V. Cossalter, R. Lot, M. Massaro, M. Peretto

V. EFFECT OF LONGITUDINAL ACCELERATIONS
When braking or accelerating the steering torque
necessary to negotiate the curve changes because the inertial
forces and torques lead to a new equilibrium configuration.
In this section the numerical model is used to compute the
equilibrium steering torque while cornering at different
speeds (5-30 m/s) and lateral accelerations (0-6 m/s2) with
two values of longitudinal accelerations, ± 6m/s2.
First the braking condition is addressed. Since the same
deceleration may be obtained with different braking
strategies, e.g. only front braking, only rear braking, 50%
front and 50% rear, etc., it has been chosen to divide the
braking effort between front and rear axle in order to have the
same longitudinal slip on both tyres. This approach is
considered the best braking strategy [24]. Figure 15 depicts
the difference between the equilibrium steering torque in
braking condition and the equilibrium steering torque
without longitudinal acceleration. It is worth noting that the
differences are significant and more pronounced as the lateral
acceleration increases. A deeper investigation reveals that the
components of the steering torque due to the gyroscopic
torques, centrifugal forces and weight forces do not change
when braking, since their magnitudes do not depend on
longitudinal acceleration and their arms are almost
unchanged. On the contrary, the five torque components
related to road-tyre interaction change significantly. Indeed
when braking on curve there is both a normal load transfer
and a lateral force transfer from the rear axle to the front axle.
While the normal load transfer is obvious, the lateral force
transfer is not. In order to make things clearer, the
expressions of the normal loads Nr,f and lateral forces Fr,f are
reported below for the simple case of a vehicle with no
aerodynamic force and null steer angle

where M is the mass, w is the wheelbase, b and h are the
coordinates of the c.g., ax is the longitudinal acceleration, ay
is the lateral acceleration, subscript r is used for the rear tyre
while subscript f is used for the front tyre.
The analysis of the torque components related to the
road-tyre interaction reveals that because of the increased
front normal load and front lateral force, both aligning and
misaligning components increase their magnitude. Anyway
the main effect is the misaligning torque due to the front
braking force (Figure 16), whereas the increment of the
aligning effect of tyre lateral force is almost balanced by the
increase of the misaligning effect of tyre normal force, and
the increment of the aligning effect of tyre rolling resistance
torque is almost balanced by the increase of the misaligning
effect of tyre yaw torque. From the dynamic point of view the
fact that the steering torque is significantly affected by the
braking effort means that there is a strong coupling between
in-plane and out of plane dynamics when braking while
cornering. Please note that this coupling is strongly
correlated to the shape of the front tyre carcass and increases
with the tyre size. The analysis also explains why when
braking on curve the vehicle is likely to naturally reduce the
roll angle. Let’s suppose a rider is running on a curve with
constant speed and constant lateral acceleration, i.e. roll
angle. At some point he brakes using the front brake, as a
consequence the new equilibrium steering torque is much
more misaligning. If the rider does not promptly adapt his
handlebar torque, the vehicle is no more in equilibrium and
the steer angle increases due to the excess of misaligning
torque. This causes an increment of the sideslip angle and of
the lateral force that tends to straighten the motorcycle [6].
When accelerating the steering torque map does not
change significantly as it does in braking condition. Indeed,
the front tyre longitudinal force is not subjected to significant
variation as while braking. As well as the other components
is concerned, they do not change the steering torque since the
situation is very similar to the braking one, with all load
transfers reversed. From the dynamic point of view the fact
that the steering torque is not significantly affected when
accelerating means that there is a weak coupling between
in-plane and out of plane dynamics when accelerating while
cornering. In other words when a rider accelerates while
cornering he does not feel the vehicle changing its roll, or at
least not as much as he feels when braking.
 

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I think everyone can easily say if something is easier to turn than something else, but would struggle to say WHY.
 

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Discussion Starter #75
speedfinn:

OK and I would like your opinion based on your own understanding and experience. Also please in layman's terms so those who are also reading this who are not so technically inclined can easily understand. Many will not necessarily understand 6 Meters/Second Squared in lateral acceleration and how much g-force that is, and therefore the resultant lean angle that might approximate, etc., etc.
 

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speedfinn:

OK and I would like your opinion based on your own understanding and experience. Also please in layman's terms so those who are also reading this who are not so technically inclined can easily understand. Many will not necessarily understand 6 Meters/Second Squared in lateral acceleration and how much g-force that is, and therefore the resultant lean angle that might approximate, etc., etc.
Well, he didn't actually WRITE that, merely copied it, so...
 

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First, define "100% braking".
That's the golden question, and I don't know the answer.

Is this 100% breaking ?

213797


213796



Or is this 100% braking ?

213798




Looking at brake pressure sensor itself, both seems to be around 80%, but speed differences are massive.

I can easily lift my rear into San Donato. Obviously it's much more difficult to do the same at lean.
 

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In your opinion is there a torque on the bars from trailing the brakes? If so, would that make it easier to steer, harder, or no difference? Also, would this change significantly with lean, for example 30 degrees versus 10 degrees.
If you tell a average track day rider, that bike turns easyer with trail braking, then that rider feels that bike turns easyer with trail braking.
If you measure the steering force, which is needed to turn the bike while trail braking, the actual force will be bigger than without trail braking.
 
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