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@speedfinn so your long (and stupid) response could have been replaced by simply saying "briefly spike" with graph attached.
Maybe the problem is that you do not have skills to analyse data? And that is why you do not understand what kind of graph proper trail braking creates?

If you can not spot the difference between a spike and a ramp... Well it is not my loss that you do not even want to try to understand...
 

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I can keep a 0.9-1g for almost 60-70 meters without spikes. It is not that bad:laugh:. Sorry I do not have brake pressure which would have been really helpful.

Mine is blue and red is from a friend of mine.

As you can see I gain with trail braking more than 0.6sec even if I come with lower speed (I need to fix this) and I have higher speed in the turn. He gains in the exit (also need to fix it:grin2:). He brakes harder and have more g of deceleration ( but he feels a bit unstable) but I am more progressive and keep a bit deeper the brakes in the turn. My feeling in this trackday was soooo good in the brakes and inside the turn, like I have never felt it before.


Data are so useful>:)
 

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Some old measurements what I have done:

Clutch egaged, air drag + rolling resitance:

Tucked down, lower body in the middle
180 kmh -0,200 G
150 kmh -0,155 G
120 kmh -0,100 G

Tucked down, lower body on the side (for the nex turn)
160 kmh -0.215 G
150 kmh -0.180 G
140 kmh -0.165 G
130 kmh -0.140 G
120 kmh -0.125 G

Braking body position (head up, knee on the side)
190 kmh -0,400 G
180 kmh -0,350 G
170 kmh -0,315 G
160 kmh -0,275 G
150 kmh -0,225 G
140 kmh -0,215 G
130 kmh -0,205 G
120 kmh -0,175 G
I'm wondering about something faster like 300km.
You can use a "simple" equation and extrapolate those numbers to any speed you like.
It should not be too hard for a wise guy.

I was planning to do the work for you, but, well, maybe later.
 

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Discussion Starter #26
@speedfinn 1) I've been trained on reading datalogger data by a BMW World Superbike Engineer. Two day intensive course. 2) I possess datalogger data for current Moto2, World Superbike, AMA Superbike and MotoGP riders and have studied them with engineers and riders. 3) I have two consulting physicists I use for difficult questions--one is about to get his PhD and the other is an aerospace engineer. This question I posed was a simpler one that I felt would be answered by a member of the forum and also stimulate a constructive discussion that we all could learn from. I could have gone to one of these other people and gotten my answer but I like knowledge to be shared in a forum for people who are actively interested in the topics.

I've been insulted by you in the past on other threads and it's getting old, mainly because they are based on your assumptions or conclusions based on incomplete data. You seem like a bright person. Take it easy.
 

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@speedfinn 1) I've been trained on reading datalogger data by a BMW World Superbike Engineer. Two day intensive course. 2) I possess datalogger data for current Moto2, World Superbike, AMA Superbike and MotoGP riders and have studied them with engineers and riders. 3) I have two consulting physicists I use for difficult questions--one is about to get his PhD and the other is an aerospace engineer. This question I posed was a simpler one that I felt would be answered by a member of the forum and also stimulate a constructive discussion that we all could learn from. I could have gone to one of these other people and gotten my answer but I like knowledge to be shared in a forum for people who are actively interested in the topics.

I've been insulted by you in the past on other threads and it's getting old, mainly because they are based on your assumptions or conclusions based on incomplete data. You seem like a bright person. Take it easy.
Um, ok, now I might guess what is the underlying problem. I assume you refer to case "cornering friction", where you said that bike slows down in a corner because of "cornering friction", not mainly because of engine brake.

And in that thread I said:"Term "cornering friction" is still totally stupid term, because most of the deceleration is usually caused by engine brake after braking. And then there is air drag (very significant only in very fast corners), and rolling resistance.
So when you start to apply throttle, you are not fighting against "cornering friction" , you are just mainly makeing engine brake smaller.
That is why that graphic of the different cornering forces is quite misleading and imperfect."

And then you left the discussion and never came back at it.

I did not realize that I hurt your feelings and still after a year you are hurt about it.
I also assume, that you still imagine that bike slows down in a corner because of mainly imaginary "cornering friction"?

So I really encourage you to contact your "BMW World Superbike Engineer", "engineers and riders", "two consulting physicists/ almost PhD and aerospace engineer", and ask them what they think about your mainly imaginary "cornering friction".
Because it seems that you have this very common problem: You just do not want to receive new information from a noname-internet-person if the information contradicts the information you have strong faith to.
There is also a sophisticated term for that behavior: Cognitive dissonance.


You also claim that I have insulted you in multiple threads?
Please let me know if there really is multiple threads, and what was the issue in those treads.
Because case "cornering friction" is the only one I remember where I might have "insulted" you by saying that a term you used is stupid (and misleading).
I really do not like false accusations.


And anyone who has 10Hz GPS or BMW Datalogger can simply test what is the reality in the case of cornering deceleration:
First find a long flat turn, pull the clutch before you turn in to the turn.
Then do the same entry speed on a flat straight, and pull the clutch.
And then compare deceleration values of those two cases.
Remember to have the same body position in both cases, because air drag plays a very significant role in deceleration when you are rolling with clutch pulled in.


And here is link to that original "cornering friction" case:
https://www.s1000rrforum.com/forum/rider-improvement-techniques/235792-crashing-z-style-rr-fun-4.html#post2294422
 

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<*~sigh*~>
If you are cornering slowly, engine braking will be greater than cornering friction. However, once you are cornering at any significant speed, this horizontal friction force is large and takes a good amount of engine power to overcome. Engine braking is a small force in comparison.
And also you are completely way off beam.

When I asked you a simple simple question:
"Can you even make guess how big is the longitudinal vector of the cornering friction for example with; s1k, dunlop slicks, 60mph, when cornering force is 1G?"

You could not even give any answer.

But let me now help you a bit.
In that situation (stock) engine brake causes deceleration, maybe something like 0.2 (low rpm) - 0.4 (high rpm) G.
Air drag causes deceleration, maybe something like 0.15-0.25 G, depending on body position.
Rolling resistance causes deceleration, maybe something like 0.02-0.05 G.
"Cornering friction" causes deceleration, maybe something like 0.01-0.03 G.

So total deceleration when going to a 60 mph corner with engine brake is something like 0,38-0,73 G.
Engine brake is 53-55% of the total deceleration.
Air drag 34-39%.
Rolling resistance 5-7%.
"Cornering friction" is 3-4%.

And if you want some other example with some other speed or configuration, just let me know. I'm glad to help you.
 

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Wrong.

I chose not to engage with you further as you are always insulting and otherwise deliberately unpleasant.

Wading through your abuse is not worth the few helpful bits which might be hidden in your posts.

Best wishes.
"First they ignore you,
then they laugh at you,
then they fight you,
then you win."
-Mahatma Gandhi-
 

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Discussion Starter #32
Hi everyone. I've been very busy with 4 school days at Thunderbolt and now we are starting 4 more days at Virginia tomorrow. Weather looks good and the HP4R has a new rear tire!

When things settle down for me schedule wise I'll check in with the guys I consult with and see if I can get a good answer to the question. If I get something useful I will share it.

Keith says hello to everyone.
 

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Come see me and say hi! I don't know who you are in the "real" world.
I said good morning! The tall skinny guy on the unpainted R6.
The only rider that had three coaches in one day. Z in case that helps ring a bell. School was great as always! Hope to see you and CSS crew at Code Race next.
 

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Hi Dylan,

When you consult with your aerodynamics experts, they're going to need to know some idea of the flat plate area presented to the relative wind to determine the amount of drag at any given speed. The flat plate area is what a silhouette looks like if viewed from the front - similar to this photo comparing my K1600GT with my S1000RR:



Obviously, the actual flat plate drag area needs to the measured with the rider on board sitting in the braking position on the bike.

That'll give them one of the variables they need to help you determine the amount of deceleration from drag. With that, weight and speed you should be able to reach the answer you're looking for.

Huge fan of your school. Repeat L4 knucklehead and you'll likely see me again next spring, maybe out on the left coast.
 

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When you consult with your aerodynamics experts, they're going to need to know some idea of the flat plate area presented to the relative wind to determine the amount of drag at any given speed.

Obviously, the actual flat plate drag area needs to the measured with the rider on board sitting in the braking position on the bike.

That'll give them one of the variables they need to help you determine the amount of deceleration from drag.
Or you can use deceleration measurements data, because "flat plate area" (the cross sectional area), and the drag coefficient are both constants in that data. It is easy to make the drag force equation out of it.

If you want to measure cross sectional area, then there is one quite simple method to do that.
Measure front fairing width above triple tree. You need this value to be able to scale the picture.
Use a camera/lens which has for example 400 mm focal length, and take a picture. Focal length must be big, otherwise perspective will effect too much.
Scale the picture so that one pixel is 1x1 mm (or 0.5x0.5).
Remove background/ make it white.
And check picture data; how many colored pixels it has.
(But then you are still missing the drag coefficient and you have to guess it...)
 

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Discussion Starter #39 (Edited)
Yo PittsDriver. Thanks very much. Have not heard back from one of them. May have to go to the other person. In any case I think we all realize this is going to be to some extent a bit of a guess because defining all factors is such a random thing. So many variables. But a rough idea is what I'm searching for.

Had a great time riding the HP4R today
 

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@PittsDriver Don't be a stranger just because you are riding a Super Duke that puts an S eating grin on your face every time you ride. :laugh: You'll be back once you ride a properly flashed, full exhaust 2020. :wink2:

Completely O/T... Why do call yourself a Driver? Isn't that some sort of put down for pilots? You have posted videos of your aerobatics. Hardly "driving." Google search was no help. While not a reputable source of reference even some episodes of JAG refereed to pilots driving F14s. :rolleyes: Shed some light please.
 
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