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Rossi: "MotoGP is boring..."

aciurczak said:
That's not a secret, it's just bad math. There's no magical pounds to hp calculation. The actual difference varies depending on the starting weight of the bike, and its current hp.

ex 1: 350 pound bike, 150 pound rider, 150 hp.

500 pounds of total weight, pushed by 150 hp. If you want to increase performance 1%, you need to lose 5 pounds. Or you need to add 1.5 hp. In this case, 1 hp = 3.3 pounds.

ex 2: 450 pounds bike 200 pound rider, 100 hp.

650 pounds total weight, pushed by 100 hp. If you want to increase perfiormance 1%, you need to lose 6.5 pounds. Or you need to add 1 hp. In this case, 1 hp = 6.5 pounds. This is the one that is closest to the "secret", as it has been close to what a "standard" road bike has made for a decade or two, whether big-bore UJM, or even a modern 600.

ex 3: 700 pound bike, 200 pound rider, 75 hp.

900 pounds total weight, pushed by 75 hp. If you want to increase performance 1%, you need to lose 9 pounds. Or you need to add .75 hp. In this case, 1 hp = 12 pounds.

add some rough gp bike specs:

ex 4: 360 pound bike, 120 pound rider, 250 hp.

480 pounds total weight, pushed by 250 hp. If you want to increase performance 1%, you need to lose 4.8 pounds. Or you need to add 2.5 hp. In this case, 1 hp = 1.96 pounds.
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That makes more sense, I never heard it broken down like that. But also consider mine 7.3 was something from an ama rider back in 2004 I believe lol.
 
aciurczak said:
Um, that was pretty much the point. There is no simple conversion factor from pounds to hp, as if there were some universal constant. To your point, even if there were such a constant, power to weight ratio isn't the only determinant of a motorcycle's performance on the track.
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then whyd you type all that dribble in support of nonsense?

sidewazzz said:
That makes more sense, I never heard it broken down like that. But also consider mine 7.3 was something from an ama rider back in 2004 I believe lol.
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NO IT DOESNT :x
 
aciurczak said:
That's not a secret, it's just bad math..
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Wow. Ya' just look reaaaaly smart, there. Except speed is not a linear equation, and IF I WANTED to make it really accurate and complicated, I could do that in a nanosecond. Now let us go back over your calculations and factor in speed SQUARED, and the coefficient of drag. Thanks.
 
That's kuz I went to skul. :)

(I also didn't mention speed once, I just said if you wanted to increase performance 1%. Depending on what is meant by performance, whether acceleration increase, top speed increase, or improvement of attractiveness to the opposite sex, all of those could improve by 1% depending on the unit of measure)

And you were the one that agreed with the phantom 7 number, genius. :)

sidewazzz said:
But also consider mine 7.3 was something from an ama rider back in 2004 I believe lol.
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The AMA paddock might not be the one-stop-shop for mathematical truthseeking. :thumbup

stangmx13 said:
then whyd you type all that dribble in support of nonsense?
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I think you mean drivel. :twofinger
 
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As one who was typically 100lbs. heavier than the competition, I'd like to see weight equalizers (weights) added at tech inspection. Heavier riders toast the tires quicker, thus, the lighter riders have a serious advantage toward the end of a race...:x
 
EastBayDave said:
As one who was typically 100lbs. heavier than the competition, I'd like to see weight equalizers (weights) added at tech inspection. Heavier riders toast the tires quicker, thus, the lighter riders have a serious advantage toward the end of a race...:x
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In a sprint race? With modern tires?

I work with an AFM rider that is probably about your size and tires are not a problem.
 
aciurczak said:
And you were the one that agreed with the phantom 7 number, genius. :)
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Well, smartipants. No one disagreed, either. And it was certainly more convenient to use HIS number to show that it didn't matter, anyway. Which was the whole point, and not to show how pedantic I could be in a motorcycle forum, where Coefficient of Drag is rarely considered, and actual performance is ignored, like with your statistics.
 
EastBayDave said:
As one who was typically 100lbs. heavier than the competition, I'd like to see weight equalizers (weights) added at tech inspection. Heavier riders toast the tires quicker, thus, the lighter riders have a serious advantage toward the end of a race...:x
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pros make these same tires last 20+ laps while going much faster. having a problem after 6 laps is an issue w/ skill and setup, not rider weight. i struggle w/ aggressive tire wear as well and im a featherweight :p
 
clutchslip said:
Well, smartipants. No one disagreed, either.
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Umm, I did. You didn't.

clutchslip said:
And it was certainly more convenient to use HIS number to show that it didn't matter, anyway. Which was the whole point, and not to show how pedantic I could be in a motorcycle forum, where Coefficient of Drag is rarely considered, and actual performance is ignored, like with your statistics.
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Get over yourself. :) All my trivial example was meant to show was a simple demonstration of F=MA discounts any rule of thumb of "x horsepower is as good as y pounds". Any other factor added on top of that would make such a rule of thumb even less possible, including the valid items you listed like Cd and any other number of parameters.
 
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EastBayDave said:
As one who was typically 100lbs. heavier than the competition, I'd like to see weight equalizers (weights) added at tech inspection. Heavier riders toast the tires quicker, thus, the lighter riders have a serious advantage toward the end of a race...:x
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Can't say I agree with that.
 
JO EBRMC said:
In a sprint race? With modern tires?

I work with an AFM rider that is probably about your size and tires are not a problem.
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That's quite a surpise to me. I retired f/racing in 84', & I'm guessing the slicks back then were no where near as good as now? I'd run high pressures to combat this & still "melt" the tires in 8 laps, especially on very hot days.

pros make these same tires last 20+ laps while going much faster. having a problem after 6 laps is an issue w/ skill and setup, not rider weight. i struggle w/ aggressive tire wear as well and im a featherweight
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Well I think the current electronics are helping in the making tires last? My speculation is more related to the MotoGP guys; think about this:

What if they all had say, a 30lb. weight attached to the lowest part of the chassis. They could then vary the weight up or down dependent of rider weight= so the featherweight guys wouldn't have such an "apparent" advantage? (my bro raced sprint cars, & they did this= it worked!)

I'm just theorizing out loud here; thinking on how to even the (apparent) HP differences between a light & a medium weight rider. I'm thinking say the diff. between say Spies & Pedro....?

What's ya think?
 
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sidewazzz said:
While you did, you only disagreed that the number was too high in terms of weight. Taking the 7.3 lbs down to 1.96 lbs to in theory = 1hp. Thus giving Pedro 15 hp advantage n theory over the 30lbs heaver Jorgay.:laughing:twofinger
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Hey now! :) I didn't say the number was too high or too low. I said the number was useless.
 
EastBayDave said:
That's quite a surpise to me. I retired f/racing in 84', & I'm guessing the slicks back then were no where near as good as now? I'd run high pressures to combat this & still "melt" the tires in 8 laps, especially on very hot days.



Well I think the current electronics are helping in the making tires last? My speculation is more related to the MotoGP guys; think about this:

What if they all had say, a 30lb. weight attached to the lowest part of the chassis. They could then vary the weight up or down dependent of rider weight= so the featherweight guys wouldn't have such an "apparent" advantage? (my bro raced sprint cars, & they did this= it worked!)

I'm just theorizing out loud here; thinking on how to even the (apparent) HP differences between a light & a medium weight rider. I'm thinking say the diff. between say Spies & Pedro....?

What's ya think?
Click to expand...


The issue here is that there hasn't been a definitive case that weight has a real impact. The other part of it is that static weight (bike and ballast) and dynamic weight (rider) affect the bike totally differently. Honda says adding 4kg of ballast seriously impacted their design (I think they overstate the issue but still...) where as a 4kg difference in rider doesn't seem to have any real impact to design.

Sort of a side note: Bridgestone is actually designing in tire wear since even their softest compounds are capable of lasting race distance - regardless of rider size.


Since there isn't anything except speculation that tells us rider weight is important, I actually believe that rider size is a more significant factor. Both Pedrosa and Elias have said that they are at a real disadvantage in trying to get weight over the rear when braking - their arms and body simply aren;t long enough. Moreover, a longer and larger torso provides better aero which, on a 240hp machine doing 210MPH could be significant, perhaps overcoming the acceleration/weight disadvantage.


All in all, midget theory (in MotoGP - there are stronger arguments in smaller displacement classes where the bikes spend much more time at WOT) is all speculation with no evidence, even anecdotal, to support it. Meanwhile the possible solutions do more harm than good and are subject to all sorts of unintended consequences.
 
JO EBRMC said:
The issue here is that there hasn't been a definitive case that weight has a real impact. The other part of it is that static weight (bike and ballast) and dynamic weight (rider) affect the bike totally differently. Honda says adding 4kg of ballast seriously impacted their design (I think they overstate the issue but still...) where as a 4kg difference in rider doesn't seem to have any real impact to design.

Sort of a side note: Bridgestone is actually designing in tire wear since even their softest compounds are capable of lasting race distance - regardless of rider size.


Since there isn't anything except speculation that tells us rider weight is important, I actually believe that rider size is a more significant factor. Both Pedrosa and Elias have said that they are at a real disadvantage in trying to get weight over the rear when braking - their arms and body simply aren;t long enough. Moreover, a longer and larger torso provides better aero which, on a 240hp machine doing 210MPH could be significant, perhaps overcoming the acceleration/weight disadvantage.


All in all, midget theory (in MotoGP - there are stronger arguments in smaller displacement classes where the bikes spend much more time at WOT) is all speculation with no evidence, even anecdotal, to support it. Meanwhile the possible solutions do more harm than good and are subject to all sorts of unintended consequences.
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Hmmm...hadn't thought about those things (aero's/braking in rear), I was thinking more:

less weight= better acceleration off corner/down straights giving an "apparent" HP advantage, better braking during braking contests (? Thinking less TOTAL mass to slow), & less tire wear when sliding it around on entrances/exits.

I mean, this whole thread is about making a better "show" for the fans, equaling (or nearing) weight total (bike & rider) wouldn't help that?
 
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