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Old 07-11-2010, 10:14 AM   #1
Kenneth_Moore
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Default How Much Horsepower

Do your brakes make?

I was watching a show called "Motorcycle Crash Tech," or something like that. They had a clip on Brembo; including a factory tour, testing, etc.

One of the Brembo engineers was talking about matching brakes to bikes. He said that a bike that makes 200 horsepower needs brakes that make from 400 to 450 horsepower.

Any mechanical engineers out there who can explain how a braking system can be measured in horsepower? I gather that horsepower is a unit of work based on how far a "standard" horse can lift a specific weight in a specific time. Or how quickly the horse can lift the weight a specific distance. Either way, relating that to brakes just doesn't make sense to me.
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Old 07-11-2010, 11:36 AM   #2
seruzawa
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I think the engineer is incorrect or at least the explanation is incomplete. You would have to figure in the mass of the bike and rider to determine how powerful the brakes need to be. A bike weighing 740 lbs traveling at 130mph would require much stronger brakes than a 350 lb bike traveling at 130mph.

The formula can be worked any way you wish. It's basically Ft-Lbs per time unit. One HP = 550lb moved 1ft per second.

All you need are brakes that will bring the total mass of the bike and rider to a stop at the edge of traction. The desired strength of the brakes would depend on the mass of the bike and it's top speed. You could calculate the force necessary to bring, say 1000lbs of bike and rider to a stop from 125mph, for example, and express it as horsepower.

Horsepower really isn't the right formula to measure acceleration and deceleration. Horsepower is a theoretical calculation of work done. Torque is what happens when you turn the throttle or apply the brakes and is more useful. In other words horsepower tells you how fast a bike can go. Torque tells you how long it will take to get there. This explains why a 100hp 1100cc bike with 80ft-lbs of torque will out accelerate a 100hp 600cc bike with 45 ft-lbs. Both may have the same top end speed.

More confused now?
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Old 07-11-2010, 02:01 PM   #3
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I would imaine they use a drum dyno set-up and messure the brake horse power similar to the way you chart rear wheel horsepower.
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Old 07-11-2010, 02:33 PM   #4
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How many horses it would take to break the brake loose?

As long as I can stop quicker than Suzy Cellphone in her Navigator can turn left.......
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Old 07-11-2010, 05:35 PM   #5
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Default Colin Chapman

Colin Chapman's philosophy was high performance through low weight.A lighter mass improves overall performance as in accelleration and shorter stopping distance. I don't see how the horsepower metric translates to brake size over the mass and motion metric. Unless the engineer feels high HP translates to a greater mass at speed metric. If someone can explain that one please do. Thanks and Tripples Rule.
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Old 07-11-2010, 05:48 PM   #6
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It's been too long ago to offer any really relevant info but I think his ratio is low. Where's an engineer when you need one?
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Old 07-11-2010, 06:23 PM   #7
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Default I think this is the answer.

What Is Brake Horsepower?

It's just a guess.
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Old 07-12-2010, 11:10 AM   #8
Kenneth_Moore
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Horsepower really isn't the right formula to measure acceleration and deceleration.

That's what I was thinking. But the Brembo guy was very specific with his language, he used HP to qualify braking force like we'd use it to characterize an engine's output.
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Old 07-13-2010, 03:50 AM   #9
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Default Horse Power

Hi,
I'm Nicole, in my point of view Horsepower is suitable for acceleration, deceleration. Now, I want to know about which company provides highest
CC for which product.
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