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LOST HIS RIDE
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You are right about braking distances of cars being shorter than that of our Ninja's. Being a noob myself it sure feels like i can stop on a dime.

Cycle World,June 2008 Road Test has the 60-0 mph braking distance at 157 ft. Which is quite a bit longer than that of most cars.

So for all the other noobs like myself , Don't tailgate!
 

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You are right about braking distances of cars being shorter than that of our Ninja's. Being a noob myself it sure feels like i can stop on a dime.

Cycle World,June 2008 Road Test has the 60-0 mph braking distance at 157 ft. Which is quite a bit longer than that of most cars.

So for all the other noobs like myself , Don't tailgate!
Yeah, who would have thunk it...4 disks with massive calipers, hydraulically assisted brake pressure, antilocking braking assist, and four massive contact patches, versus about 3cm of contact patch and ONE rotor with ONE tiny little caliper...just doesn't make sense. :rolleyes:

Sorry, I just find it ironic that we're now handing out reps for common sense. I knew it was a rarity, but I guess I just didn't know HOW rare. :D

















Okay okay, I kid I kid.:D
 

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I am shocked and dismayed that anyone who has read enzo's posts (in particular the rare ones where he is actually being serious) would have any doubt that the man knows his stuff when it comes to motorcycles and how to ride them.
While it is difficult to discern what is truth and what is just entertaining fiction at times, unembellished statements from him (as in this case) should always be taken as accurate, unless one truly enjoys the taste of crow. :p
 

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I'm not gonna jump on the "250 guys don't have common sense" bandwagon :rolleyes:.

When I read that post of Enzo's, I felt it was implied that not everyone realizes that cars can stop quicker...not sure why that is so shocking to ya'll.

Of course the logic is flawed, but people could easily think that motorcycles are lighter...therefore can stop faster. Using the same logic that a car stops faster than a truck. I'd be willing to bet that if someone started a poll in the two-wheeled section you'd get a lot of votes on both side of the equation. Just sayin'.

Now...for a discussion: I'm going to argue that motorcycles can and might stop as fast or faster than cars despite the lack of anti-lock brakes/more contact surface.

A motorcyclist has his fingers on the brake and only has to move it 1.5 inches in a panic whereas a cage driver has to lift his foot from the accelerator, move it to the brake, and then depress. Braking distance tests don't factor in reaction times.

What say you?

:)
 

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I'm pretty sure it used to be the other way around and bikes could always out-brake cars. With the advent of 4-wheel disc brakes and anti-lock though, there are many cars that can stop shorter now. Surprising since the average weight of cars has actually increased in the past couple of decades. Lots of people are holding on to their cars longer because of the economy, so you can still stop shorter than a lot of older cars on the road.
 

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I'm not gonna jump on the "250 guys don't have common sense" bandwagon :rolleyes:.

When I read that post of Enzo's, I felt it was implied that not everyone realizes that cars can stop quicker...not sure why that is so shocking to ya'll.

Of course the logic is flawed, but people could easily think that motorcycles are lighter...therefore can stop faster. Using the same logic that a car stops faster than a truck. I'd be willing to bet that if someone started a poll in the two-wheeled section you'd get a lot of votes on both side of the equation. Just sayin'.

Now...for a discussion: I'm going to argue that motorcycles can and might stop as fast or faster than cars despite the lack of anti-lock brakes/more contact surface.

A motorcyclist has his fingers on the brake and only has to move it 1.5 inches in a panic whereas a cage driver has to lift his foot from the accelerator, move it to the brake, and then depress. Braking distance tests don't factor in reaction times.

What say you?

:)
This one is easy. I'll use one of my cars, you use your bike. I'll either ride your ass or you ride mine. Someone will yell stop and we both hit the brakes. Do you want to be in front or back?
 

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This one is easy. I'll use one of my cars, you use your bike. I'll either ride your ass or you ride mine. Someone will yell stop and we both hit the brakes. Do you want to be in front or back?
Sucker Bet Alert! Don't do it Soup. He'll bring the Testarossa or the Lamborghini.
 

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I'm not gonna jump on the "250 guys don't have common sense" bandwagon :rolleyes:.

When I read that post of Enzo's, I felt it was implied that not everyone realizes that cars can stop quicker...not sure why that is so shocking to ya'll.

Of course the logic is flawed, but people could easily think that motorcycles are lighter...therefore can stop faster. Using the same logic that a car stops faster than a truck. I'd be willing to bet that if someone started a poll in the two-wheeled section you'd get a lot of votes on both side of the equation. Just sayin'.

Now...for a discussion: I'm going to argue that motorcycles can and might stop as fast or faster than cars despite the lack of anti-lock brakes/more contact surface.

A motorcyclist has his fingers on the brake and only has to move it 1.5 inches in a panic whereas a cage driver has to lift his foot from the accelerator, move it to the brake, and then depress. Braking distance tests don't factor in reaction times.

What say you?

:)
Good post. I agree it's not common knowledge amounst all riders that cars have shorter braking distances.
Despite braking differences tailgating is never justified on public streets. Even if your bike could out brake the car, you will have to react to the situation and will already be behind the clock as the car driver has already initiated the stopping process before you.
Otherwise I guess its possible a motorcyclist might be able to react quicker, than a car driver, but all the car driver has to do is slam the brakes. A motorcyclist in a panic stop still has to control the motorcycle and exercise brake management to prevent a lock up and/or a lifting of the rear wheel. ABS improves your odds for a controlled safe panic stop. Reguardless four tires with a bigger footprint likely negates any other small advantages of the motorcyclist.
Just my 2 cents, Bill
 

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What say you?
You're talking about a hundredth of a second, if that. On a bike braking isn't as simple as all that...it may seem like it, but you have to sit up, roll off the throttle, pivot your hand forward and grab the brake, then depress in two different directions (thumb/palm forward, fingers back) to actuate the brake while being conscious of not grabbing too much and either locking the front or (on more sport-tuned bikes than the 250) flipping your ass over the handlebars in a 12-o-clock endo. If the rear end comes up you will start losing braking force so you'll have to decrease your braking beyond neutral to let it set back down then re-apply the brakes to full force...you can use the rear brake in tandem to settle the chassis so it doesn't pitch as badly (providing you didn't remove it, that is), but then you're talking about balancing the front and rear brakes without locking either end while shifting the weight balance between the two.

In a car, it's as simple as going "OMFG!!!1!!11!" and using your fast-twitch relatively massive leg muscles to snap your anle up off the accelerator and slam onto the brakes as hard as you can, then just sit tight.

Honestly, I'd be willing to bet that, given equal honest reaction times (i.e. observation to start of action), a car will reach maximum braking potential quite a few hundredths, or even a few tenths before the bike will, and will maintain maximum braking force far more consistently and reliably. A motorcycle's ability to brake quickly is actually very far removed from a rider's ability to GET that motorcycle to brake quickly. Rossi on a motorcycle might be able to outbrake joe-schmoe-250-rider in a cage, but apples to apples the cage will most likely win every time.

Either way, at 60mph you're talking about 8.8 feet per TENTH...or about 10 inches per hundredth of a second. The difference in reaction time probably wouldn't be that significant either way.
 

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Common sense says it takes less force to stop a 333 lb moving bike than it would to stop a 3000 lb moving car. Dividing out 3000/333 shows it's about 9x less. And a car has 2 pairs of brakes, so each front rear/pair would provide ~4.5x more stopping force than a bike's. It's hard to tell by common sense whether a car's brakes can provide more or less than that factor just by looking at it.

Simple physics proof with both vehicles going 60 mph:

KE = 0.5mv^2
KEbike = 0.5(333)(60)^2 = 599,400 lb-mph^2
KEcar = 0.5(3000)(60)^2 = 5,400,000 lb-mph^2

Assume we try to stop both vehicle types in 100 ft. What is the relationship of the force required to stop the bike versus the force required to stop the car?

KE = W = Fd
=> d = KE/F

set dcar = dbike = 100 ft
=> KEbike/Fbike = KEcar/Fcar
599,400/Fbike = 5,400,000/Fcar
599,400Fcar = 5,400,000Fbike
Fbike = .111Fcar ~= (1/9)Fcar

The stopping force required to stop a 250R is approximately 1/9 that of a 3000 lb car.


--
KE = Kinetic Energy
m = mass
v = velocity
W = Work
F = Force
d = distance
 

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Common sense says it takes less brake force to stop a 333 lb moving bike than it would to stop a 3000 lb moving car. Dividing out 3000/333 shows it's about 9x less. And a car has 2 pairs of brakes, so each front rear/pair would provide ~4.5x more stopping force than a bike's. It's hard to tell by common sense whether a car's brakes can provide more or less than that factor just by looking at it.

Simple physics proof:

KE = 0.5mv^2
KEbike = 0.5(333)(60)^2 = 599,400 lb-mph^2
KEcar = -.5(3000)(60)^2 = 5,400,000 lb-mph^2

Assume we try to stop both vehicle types in 100 ft. What is the relationship of the force required to stop the bike versus the force required to stop the car?

KE = W = Fd
=> d = KE/F

set dcar = dbike = 100 ft
=> KEbike/Fbike = KEcar/Fcar
599,400/Fbike = 5,400,000/Fcar
599,400Fcar = 5,400,000Fbike
Fbike = .111Fcar ~= (1/9)Fcar

The brake force required to stop a 250R is approximately 1/9 that of a car.

--
KE = Kinetic Energy
m = mass
v = velocity
W = Work
F = Force
d = distance

That's some of the shoddyest physics I've seen since highschool. Those figures don't take into account brake balance, braking force on the rear brake of a motorcycle, amount of contact patch generating static friction, weight shift, or how weight shift affects static friction, plus they assume it's impossible to lock the tire and lose static friction. Refactor it given an average of 840mm of contact surface for the vehicle versus roughly ... to be generous ... 30 mm front and 60mm rear surface on the bike for static friction, plus the lack of stopping force in the rear brake plus the fact that braking shifts weight to the front, lessening your rear contact patch on the motorcycle (but not on the car) and narrowing the gap between terminal static friction and the point where it breaks friction and becomes kinetic friction. And to really make an accurate portrayal, you'll have to factor in the riders' weight, the balance of the car, the balance and weight shift on braking, how the rider distributes his weight, spring rates and damper rates in the suspension regarding how it distributes the sprung weight of each vehicle, how vehicular downforce would assist a car's braking at speed and be neutral with the motorcycle, etc. You in effect took an incredibly complex physics problem and stripped away everything (including just about everything that common sense would lend you regarding contact surface and motorcycle weight shift) that gives the massive advantage to the car.
 

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Wow I wouldn't have envisioned this thread going in this direction...

... I could've guessed it going astray, but damn. You guys are waxing physics now.
 

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That's some of the shoddyest physics I've seen since highschool. Those figures don't take into account brake balance, braking force on the rear brake of a motorcycle, amount of contact patch generating static friction, weight shift, or how weight shift affects static friction, plus they assume it's impossible to lock the tire and lose static friction. Refactor it given an average of 840mm of contact surface for the vehicle versus roughly ... to be generous ... 30 mm front and 60mm rear surface on the bike for static friction, plus the lack of stopping force in the rear brake plus the fact that braking shifts weight to the front, lessening your rear contact patch on the motorcycle (but not on the car) and narrowing the gap between terminal static friction and the point where it breaks friction and becomes kinetic friction. And to really make an accurate portrayal, you'll have to factor in the riders' weight, the balance of the car, the balance and weight shift on braking, how the rider distributes his weight, spring rates and damper rates in the suspension regarding how it distributes the sprung weight of each vehicle, how vehicular downforce would assist a car's braking at speed and be neutral with the motorcycle, etc. You in effect took an incredibly complex physics problem and stripped away everything (including just about everything that common sense would lend you regarding contact surface and motorcycle weight shift) that gives the massive advantage to the car.
I'm sorry, are any of my numbers wrong? (Except the 4.5 factor, brake force on one side of a car still effects the other side but it was to simplify) I agree many things are missing, but it's the first logical step anyone would have to take. It was the best I could do with the numbers I had. I didn't intentionally "strip away" anything. Besides words, what solid number conclusions can you give me?

Dynamics analysis would have to be done to find an answer which "common sense" could not lend you. You just helped me prove that you contradict yourself.
 

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I'm sorry, are any of my numbers wrong? (Except the 4.5 factor, brake force on one side of a car still effects the other side but it was to simplify) That's the best I could do with what I had. Besides words, what solid number conclusions can you give me? I didn't strip away anything. I agree many things are missing, but it's the best I could do with what I had.

Extensive dynamic physics calculations would have to be done to find an answer which "common sense" could not lend you. You just helped me prove that you contradict yourself.
:sigh: Okay...it's silly to think that the size of the tires on the ground doesn't have an effect on how much braking force can be physically applied. You didn't factor that in. Common sense, not a part of your equation. I'm sorry for contradicting myself. Oh wait.
 

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I've no response to the physics...

you can still stop shorter than a lot of older cars on the road.
I just randomly picked these...60-0 braking distances...weird
2005 Subaru Outback 155 ft
1997 Chevy Malibu 124 ft
2004 Ford F-150 Superduty 150 ft

This one is easy. I'll use one of my cars, you use your bike. I'll either ride your ass or you ride mine. Someone will yell stop and we both hit the brakes. Do you want to be in front or back?
Tough call :D Will either one of us be drinking?
Sucker Bet Alert! Don't do it Soup. He'll bring the Testarossa or the Lamborghini.
In that case, I'll take the front. I can use my superior reaction skillz to endo my rear wheel up onto the hood averting the danger of 1)him intentionally not stopping:mad: (most likely) or 2) me being right.:rolleyes: It's a win/win.

You're talking about a hundredth of a second, if that. On a bike braking isn't as simple as all that...it may seem like it, but you have to sit up, roll off the throttle, pivot your hand forward and grab the brake, then depress in two different directions (thumb/palm forward, fingers back) to actuate the brake while being conscious of not grabbing too much and either locking the front or (on more sport-tuned bikes than the 250) flipping your ass over the handlebars in a 12-o-clock endo. If the rear end comes up you will start losing braking force so you'll have to decrease your braking beyond neutral to let it set back down then re-apply the brakes to full force...you can use the rear brake in tandem to settle the chassis so it doesn't pitch as badly (providing you didn't remove it, that is), but then you're talking about balancing the front and rear brakes without locking either end while shifting the weight balance between the two.

In a car, it's as simple as going "OMFG!!!1!!11!" and using your fast-twitch relatively massive leg muscles to snap your anle up off the accelerator and slam onto the brakes as hard as you can, then just sit tight.

Honestly, I'd be willing to bet that, given equal honest reaction times (i.e. observation to start of action), a car will reach maximum braking potential quite a few hundredths, or even a few tenths before the bike will, and will maintain maximum braking force far more consistently and reliably. A motorcycle's ability to brake quickly is actually very far removed from a rider's ability to GET that motorcycle to brake quickly. Rossi on a motorcycle might be able to outbrake joe-schmoe-250-rider in a cage, but apples to apples the cage will most likely win every time.

Either way, at 60mph you're talking about 8.8 feet per TENTH...or about 10 inches per hundredth of a second. The difference in reaction time probably wouldn't be that significant either way.
Good input. Ok, I'll agree for the most part.
However, I'll argue that reaction times for bikers vs cagers will largely be in the bikers favor mostly because I think that bikers are much more defensive and in-tune with operating the vehicle. A cager is more apt to be on the phone, radio, conversation with passenger, daydreaming, etc. I think that reaction time will be way more significant than just inches. IMO (its the internet ya know) :p
Your point about oversimplifying the act of pulling the brake lever is well taken.:)
 

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:sigh: Okay...it's silly to think that the size of the tires on the ground doesn't have an effect on how much braking force can be physically applied. You didn't factor that in. Common sense, not a part of your equation. I'm sorry for contradicting myself. Oh wait.
I agree, tires are a significantly huge factor in the stopping power, but ALL of that is lumped into the 9x factor. All those things you say are missing are summation components in the Force equation. We can start with

Fstopping = Ffriction + Fbrakes

And Ffriction can be broken down to components and Fbrakes can be broken down as well but we don't have the model for those things nor do we have the numbers to plug into the model. But I did have correct numbers to get a correct force factor. You just have to set the number I found equal to all those things you say I stripped away but at the end of the day my force factor still stands correct. I found a number that has more backing than a bunch of "common sense" words. BOTTOM LINE: common sense won't answer the whole problem.
 
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Wow I wouldn't have envisioned this thread going in this direction...

... I could've guessed it going astray, but damn. You guys are waxing physics now.
Ohhh, I got a wax on Friday... it hurt like a bitch, but I love the end result!

There you go Vex-is that the astray you were wanting?
 
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